
O L 

CLARENCE M00RE5 W 






Class __J^_..U 4-4 1 

Book ^^^^i_35 

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COPYRIGHT DEPOSIT. 



NATURE BIOGRAPHIES 



n 




NATURE BIOGRAPHIES 

THE LIVES OF SOME EVERY- 
DAY BUTTERFLIES: MOTHS: 
GRASSHOPPERS AND FLIES 



BY 

CLARENCE MOORES WEED 

AUTHOR OF "TEN NEW ENGLAND BLOSSOMS," " LIFE HISTORIES OF AMERICAN 

INSECTS," ETC. 



Wiit^ 150 I3l)otocrapi)ic Mwtiatiom bp t^e auti)or 




NEW YORK 
DOUBLEDAY, PAGE & COMPANY 

I 90 I 



THE LIBRARY OF 
CONGRESS, 

Two Copies Received 

JUN. 20 1901 

Copyright entry 

^ CLASS ^XXc N». 

COPY B. 



Copyright, 1901, 
By clarence MOORES WEED. 

June, 1901. 



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J. S. Cushinj; & Co. — Berwick & Smith 
Norwood iMass U S.A. 



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NOTE. 

Acknowledgment should be made of the fact that several 
of these studies have been first published in The Saturday 
Evening Post, OiUing, The Journal of Edncatio7i, and TJie 
Gratzite Monthly, and are here used through the courtesy of the 
editors of these journals. Parts of two or three of the others 
first appeared in the official Bulletin of the New Hampshire 
College Experiment Station. 




k,_i-«^ 



CONTENTS. 

CHAPTER I. 

PAGE 

The Making of a Butterfly i 

CHAPTER II. 
The Viceroy Butterfly .11 

CHAPTER III. 
The American Tent Caterpillar 22 

CHAPTER IV. 
A Rural Impostor ........... 35 

CHAPTER V. 
A Devastator of Forests 40 

CHAPTER VI. 

Studies of Walking-sticks . . - . . . . . • 58 

CHAPTER VII. 
The Choke-cherry Tent-maker . .64 

CHAPTER VIII. 
The Antiopa or Mourning-cloak Butterfly 71 

CHAPTER IX. 

Locust Mummies 89 

ix 



Contents. 



CHAPTER X. 

PAGE 

Catching Butterflies with a Camera 



. . . 96 



CHAPTER XI. 
An Insect Potter 

CHAPTER XII. 

The Camera and the Entomolo2:ist 



CHAPTER XIV. 
Insects in Winter 



102 



[07 



CHAPTER XIII. 
Studies of Insect Parasites 122 



132 



NATURE BIOGRAPHIES. 



THE MAKING OF A BUTTERFLY. 

^ " To the Greeks of old as to the moderns 

. '\^^^ . of to-day and many enlightened people 

--^ nW^fcif'lt' ^^ ^^^ ^^^ intervening ages, the making 
,^ ; , a j^B^^*^ of a butterfly has ever been one of the 
^S^p^B most wonderful thinq;s in this wonder- 
__ ful world. The secret by which an 

F unattractive, sluglike caterpillar is in 

the course of two brief weeks trans- 
formed into the most ethereal of the children of the air, 
on whose translucent membranes Nature has delighted 
to paint such delicate and beautiful colours, seems likely 
ever to remain a mystery of mysteries. Were we able 
to understand it " all in all," then should we get at the 
secret of creation just as surely as would Tennyson had 
he known in its completeness that famous " flower in the 
crannied wall." 

In its external features the life of a butterfly is sufifi- 
ciently familiar to many people. It starts with an ^^<g 
laid by the mother insect upon the leaf of an appropriate 
food-plant. The ^gg shortly hatches into a tiny cater- 
pillar, that begins this second stage in its life-history as 
an elongate larva, strange in form and void of any resem- 
blance to the parent from which so shortly before it 
came. The larva feeds and grows. In a few days its 



Nature Biographies. 

skin is stretched on account of the increase in size, for 
with insects and related creatures the skin is not con- 
tinually increased from growth within itself. Instead of 
this a new skin is formed beneath the old one, and the 
latter is sloughed off — much as a snake from time to 
time casts its scaly covering. 

In this moulting process the skin upon the head splits 
apart along the middle line of the upper surface, and the 
break is continued straight backward through several of 
the body rings. By various more or less violent move- 
ments the caterpillar manages to withdraw its head from 
the old covering, and then to escape entirely, leaving the 
cast skin — an exuvium the naturalists call it — at one 
side. In the case of many species, the caterpillar, after 
resting awhile for parts of its new covering to harden, 
calmly eats its exuvium, presumably that the presence 
of the latter may not be a sign to some bird or other 
enemy that a caterpillar is in the neighbourhood. 

The larva is now much larger than it was before. After 
recovering from the stress of moulting, it again begins to 
devour the food-plant, feeding more ravenously, and con- 
tinuing to eat, with intervals of rest, for about a week. 
Then it has so increased in size that another moult is 
necessary, and this is gone through with in the same 
way as before. During the next three or four weeks this 
operation is repeated twice or thrice — making a total of 
four or five moults during the period from the ^^^ to the 
full-grown caterpillar. 

After the last of these larval moults the caterpillar feeds 
for a week or ten days. Then apparently the prodigious 
appetite it has shown throughout its life becomes satis- 
fied, for the insect becomes restless and wanders about. 
It is searching for some sort of shelter where it may 

2 



The Making of a Butterfly. 

spend the quiet pupal period, when it will be utterly help- 
less to escape the attack of its many enemies. Having 
found a sheltered corner of a fence, or some similar situa- 
tion, it proceeds to spin a silken web upon the under side 
of the chosen board, in which a little later it entanglesits 
hind feet and hangs downward preparatory to becoming 
a chrysalis. The bare outline that I have thus given 
would apply to many species of butterfhes. Among 




Fig. 2. — Monarch Butterfly at Rest upon a Poplar Twig. 

others, it fits the beautiful Monarch Butteri^y,^ so familiar 
of every one who goes afield from midsummer until 
autumn. The eggs of this regal insect are deposited on 
the leaves of milkweed, upon the substance of which the 
resulting caterpillars feed from the time of hatching until 
they become full grown. For the remainder of this ac- 
count of the making of a butterfly I wish to describe this 
species in particular, because I have been able to get the 
accompanying photographs to illustrate the description. 

1 Danais flexippus Linne (£>. arcliippus Fabiicius). 
3 



Nature Biographies. 




Fig. 3. 



Caterpillar feeding upon Leaf of 
Milkweed. 



The full-grown caterpillar of the monarch butterfly is 

a good-sized black and white insect about two inches long, 

and of the general ap- 
pearance shown in the 
picture (Fig. 3). It spins 
— sometimes upon the 
under surface of the 
milkweed leaf, some- 
times elsewhere — a lit- 
tle mat of silk in which 
it entangles the hooked 
claws of its hind feet. 
Then it lets go with 
its fore feet, and hangs 
downward with the front 

end of its body curled upward as in Figure 4. In 

this position it remains for some hours — perhaps a 

day — the body-juices gravitating downw^ard and causing 

a swollen appearance on the 

lowTr segments. Then the 

skin splits apart again, and it 

is wriggled off by the contor- 
tions of the body. When it 

finally drops away, there is 

left a strange-looking creature, 

broader below than above, 

whose appearance is shown 

in the picture (Fig. 5). This 

is a transition stage that lasts 

but a very short time : soon 

the form is entirely changed, 

so that the broadest part is 

above instead of below. The 

. • 4 




- Caterpillar hung up for the 
Change to the Chrysalis. 



The Making of a Butterfly. 

definite outline of the chrysaHs is soon taken on, the 
outer tissues hardening into a distinct covering. The 





Fig. 5. — The Transit! 



Fig. 6. — The ChrysaHs. 



insect now looks hke Figure 6 : in colour, it is a beautiful 

green with wonderful golden spots upon its surface, and 

a few black spots just below the 

black cremaster by which the 

chrysalis is connected with the web 

of silk upon the leaf. The black 

spots, the cremaster, and the white 

silken web are plainly shown in 

the picture. 

In this quiet chrysalis the in- 
sect remains for nearly a fortnight. 
Then the structure of the forth- 
coming butterfly begins to show 
through the thin outer covering (Fig. 7), and you know 
that the period of the chrysalis is nearly ended. If you 

-^ 5 




Fig. 7. — Chrysalis, showing 
Butterfly ready to emerge. 



Nature Biographies. 

keep watch you will probably see the sudden bursting 
of the outer envelope and the quick grasping of its 
surface by the legs of the newly emerged butterfly 
(Fig. 8). Its wings at first are short and crumpled, 
bearing little resemblance to those of the fully devel- 
oped butterfly. But as it hangs there with one pair 
of legs holding to the empty chrysalis and the other 





Fig. 8. — Butterfly just out of Chrysalis. 



Fig. 9. — Same, a little Later. 



to the leaf above, the wings rapidly lengthen, hang- 
ing limply downward as the body-juices penetrate the 
veins. A little later they expand in the other direc- 
tion, the hind wings reaching full size before the front 
ones, as may be seen in Figures 1 2 and 1 3. Finally both 
pairs of wings are fully expanded, and the butterfly is 
likely to walk to the top of the support, where it rests 
for an hour or two while its tissues harden, before it 
attempts to fly. 

Such, in brief outline, is the process by w^iich a butter- 

6 



The Making of a Butterfly. 

fly is made, so far as it is to be determined by external 
observation. But these are only the visible results of 
invisible internal processes, of the nature of which we 
could scarcely hazard a guess from the most careful out- 
ward scrutiny. To learn of these internal developments 
many specimens in different periods of growth have to 




Fig. io, — Butterfly with Wings 
nearly Full Length. 



Fig. I r, — A Front View, still 
Later. 



he sacrificed to the microtome and microscope, so that 
by careful study the variation in the structure and posi- 
tion of the minute cells of which the insect is composed 
may be determined. During recent years great prog- 
ress in such knowledge has been made, so that we have 
a fairly complete idea of the method of development, 
although we do not know, and perhaps shall never know, 
the " all in all " of the marvellous process. 

It is probable that ever since men have studied nature 

7 



Nature Biographies. 



critically, there have been attempts to explain the way in 
which a butterfly is made. Nearly two centuries ago, 
Swammerdam, the great Dutch naturalist, studied very 
carefully the development of butterflies and other insects. 
He found that if he placed in boiling water a caterpillar 
that was ready to pupate, the outer skin could easily be 

removed, revealing be- 
neath the immature 
butterfly with its legs 
and antennae. This led 
him to believe that the 
process of development 
was simply a process of 
unfolding ; that is, as 
Professor Packard has 
put it, ''that the form of 
the larva, pupa, and 
imago preexisted in the 
ecror and even in the 
ovary ; and that the in- 
sects in these stages 
were distinct animals, 
contained one inside the 
other, like a nest of 
boxes, or a series of envelopes, one within the other, 
or, to use Swammerdam's own words, ''Animal in ani- 
mali, sen papilio intra eriicam i^econdittisy ^ This was 
called the emboitemcnt or incasement theory, and for 
nearly a hundred years it was held by naturalists to be 
correct. Early in the nineteenth century, however, it 
was discredited by Herold, who studied carefully the 
development of butterflies; but it was not until 1864 

1 Text-book of Entomology, p. 641. 




P^iG. 12. 



Side View, F'ront Wings not 
fully developed. 



The Making of a Butterfly. 




that it was definitely replaced by another and much 
more convincing theory propounded by Weismann, the 
great German zoologist. 
By careful studies, in 
which the modern meth- 
ods of microscopic re- 
search were employed, 
Professor Weismann 
found that instead of 
the organs of the adult 
butterfly being present 
in the caterpillar, they 
really result from the 
breaking down of the va- 
rious tissues of the larva, 
followed by a remarkable 
process of rebuilding, in 
which the starting-points 
are certain germinal buds 
or " imaginal disks." This theory has entirely replaced 

the incasement theory in the 
minds of naturalists. The ger- 
minal buds appear very early in 
the life of the insect, sometimes 
even before it hatches from the 
egg. They remain with little 
change throughout the growth of 
the caterpillar. Just before the 
period of pupation, the various 
organs of the larva are broken 
down by the action of the blood 
corpuscles, the result of their destruction being a creamy 
mass which is immediately utilized for the rebuilding of 

9 



Fig. 13. — Side View, a little Later. 




Fig. 14. — The Empty Chrysalis. 



Nature Biographies. 

the tissues. During the process of destruction of the 
larval organs the germinal buds remain intact, and simul- 
taneously they begin to grow by building themselves up 
from the cream)^ material surrounding them. In this 
way the buds develop in a short time into the various 
organs of the butterfly. 



10 




THE VICEROY BUTTERFLY. 

^ .. HE Viceroy Butterfly^ is a familiar 
insect throughout most regions of 
the United States. In appearance 
and habits it reminds one of the 
larger monarch — which in truth 
it mimics — being found in open 
fields and meadows, especially along 
small willow-bordered streams. In 
such situations it sails leisurely 
about, stopping now and then to 
sip nectar from a flower, or per- 
chance to deposit an Qgg on the tip of a leaf upon a 
willow or poplar twig. In the late summer months it 
often flies under apple trees to sip the juices of the 
decaying fruit. 

If the egg upon the wallow leaf happens to have been 
laid by one of the first of the season's butterflies, it 
hatches in a few days — generally a week — into a tiny 
caterpillar that gnaws a hole out of the side of the egg- 
shell, and after it has escaped turns round and eats the 
remainder of the shell. Probably, as Mr. Scudder has 
suggested, this peculiar meal is taken to prevent the 
presence of the empty shell from notifying some enemy 
— perhaps an ant, possibly an ichneumon — that a young 
caterpillar is in the vicinity. After this dry repast, it is 
ready for more succulent food, and this it finds right at 
hand in the leaf it is resting upon. Here it feeds, eating 

1 Liinenitis disippiis Godart. 
I I 



Nature Biographies. 




Fig. 15. — Viceroy Caterpillar feeding on 
Poplar Leaf, 



the sides of the leaf near the tip, but letting the de- 
nuded midrib remain. When its appetite is satisfied it 

retires to the lower sur- 
face of the leaf, where it 
rests motionless upon the 
midrib. Throughout the 
day, when its enemies 
could easily see it if it 
moved, it remains quietly 
on its resting-place, feed- 
ing chiefly under cover of 
darkness. In about a 
week it moults, eating 
the cast skin, and soon 
beoins ao^ain to devour 
the succulent leaf tissues. 
These young caterpil- 
lars have the curious habit of fastening a few bits of leaf 
together by means of silken threads, and then fastening 
the bunch to the denuded 
rib of the leaf. Such little 
packets are shown in Figure 
18 on the lower left-hand 
leaf, and in Figures 15 and 
16 near the middle, behind 
the vertical leaf stem. To 
explain this I want to quote 
from an admirable essay by 
Mr. Samuel H. Scudder, 
whose studies of butterflies 
have done so much for our 
knowledge of these beauti- 
ful creatures : — 




Fig. 16. — Same, Another View. 



12 



The Viceroy Butterfly. 



" Soon after birth," writes Mr. Scudder, " when it has 
eaten but a very few swaths down the leaf, the little 
fellow constructs a small and loose packet from minute 
bits of leaf and other rejectamenta, loosely fastened to 
one another and to the midrib, close to but scarcely 
touching the eaten edge of the leaf ; and as fast as the 
leaf is eaten, it removes this packet (continually added 
to until it becomes almost as big as a small pea) farther 
and farther down the midrib away from its perch, always 
keeping it near the eaten edge. 
It should be noted that it is so 
loosely attached (the bits of leaf 
at all possible angles) that it is 
moved by the least breath. Mean- 
while the caterpillar has been 
growing larger and more conspic- 
uous, and thus in greater peril 
from its enemies. There are two 
possible services that this odd 
packet may render. A spider 
wandering over a leaf and ob- 
serving its motion may seize it, 
and thinking it has a prize, hurry 

away with it and leave its architect unharmed. This 
seems to me rather a strained suggestion, for a wan- 
dering spider would probably proceed to investigate it 
on the spot. Another explanation seems more probable. 
It should be remembered that the leaves preferred by 
these creatures as food are mostly such as are easily 
shaken by the wind, and as the caterpillar moves with 
the leaf and with all the surrounding leaves (in a con- 
tinual fluttering in the case of the trembling aspen, and 
to a less degree in the other food-plants) this of itself is 

13 




Fig. 17. — Young Viceroy Cater- 
pillar resting on Poplar Leaf. 



Nature Biographies. 



a protection to it, as it would more readily escape obser- 
vation as an object distinct from the leaves, all being in 
motion together ; but on the more stable leaves, like the 

willow, the mo- 
tion in a feeble 
wind would not 
be sufficient to 
be serviceable, 
and here, at 
least, the pack- 
et comes into 
play. An ob- 
ject in motion 
among others 
at rest is a no- 
ticeable thing ; 
a fact well rec- 
ognized among 
animals, as a 
host of them 
show w hen 
they fear being 
seen. This 
packet at- 
tached by loose 
silken threads 
m o V e s, as 
stated, with a 
breath of wind, 
and so would 
distract atten- 
tion from its 

Fig. 1 8. — Viceroy Caterpillar resting on Poplar Twig. architect near 




The Viceroy Butterfly. 



by, who has taken pains to place it at the farthest 
remove from his perch, while still (to avoid undesirable 
steps) on his daily track. If this be really its object, it 
is surely one of the oddest devices in nature." 

The caterpillars of this early summer brood continue 
to feed and grow, moulting twice more, at intervals of a 
week. As they become 
larger the two spiny horns 
just back of the head be- 
come more conspicuous, 
and the general colour be- 
comes a peculiar mottled 
combination of greenish 
olive and gray, the darker 
colour being at each end and 
the lighter in the middle, 
as may be seen by reference 
to the accompanying pic- 
tures of these caterpillars. 
When the insect gets too 
large to rest in comfort and 
safety upon the midrib of 
the leaf, it spends its days 
upon the twigs, resting 
quietly for hours, head downward, in such positions as 
are shown in Figures i8and 19. The colouring of the 
insect is such as to suggest a bit of bird dung, and the 
resemblance is made more marked by its form and 
the attitudes it assumes. This resemblance, probably, 
proves a source of protection from some birds and other 
enemies. 

When the larva becomes full grown, it spins a web of 
silk upon the bark of the twig, upon the leaves of which 

15 




Fig. 19. — Viceroy Caterpillar resting on 
Poplar Twig, Another Position. 



Nature Biographies. 

it has been feeding. In this it entangles the hooked claws 
of its hind legs and hangs downward in the position shown 
in Figure 20. Here it remains for a while before the 
skin along the back splits open and is wriggled off, leav- 
ing the insect suspended in the peculiar form shown in 
Figure 21. This transition stage is of short duration: 





Fig. 20, — Viceroy Caterpillar hung 
up for Pupation. 



Fig. 21. — Transition Stage between 
Larva and Chrysalis. 



very soon the definite form of the chrysalis is assumed 
(Fig. 22). 

The colours of the chrysalis are very much like those 
of the larva — such a mottling of gray and olive-green 
that the creature still resembles a bit of bird dung. The 
most peculiar thing about the shape of this stage of the 
insect is the large projection on the middle of the back. 

The pupa state lasts only about a week. Then the 

16 



The Viceroy Butterfly. 



butterfly emerges, hanging on the 
adjacent twig, until its wings are 
walks upward toward the tip, wher 
hour or so, as showai in 
Figure 23, before tak- 
ing its first flight into 
the new and airy world 
into which it finds itself 
born. The forsaken 
chrysalis still hangs — 
an empty tenement, per- 
fect in outward form, 
with only the cracks 
along the front to indi- 
cate where the occupant 
escaped (Fig. 25). 

The butterflies that 
thus appear in August 
belong to the second 
brood of the season. 
They remain upon the 
wing for some time, lay- 
ing eggs during the 
later days of their life 
on the same kinds of ; 
food-plants that they 
developed upon. These 
eggs hatch into little 
caterpillars, that feed 
upon the terminal parts 
of the leaves, in the 
same way that the 
earlier bmod did. But 



empty chrysalis or the 
of full size. Then it 
e it is likely to rest an 




Fig. 22. — 



The Chrysalis of the Viceroy 
Butterfly. 



•7 



Nature Biographies. 



when they are about one-third grown, they do something 
that was not done by the preceding generation — they 
build special houses in which to spend the winter. This 
is so curious and interesting a fact in the hfe-history of 

the species, that I want 
to quote the original 
account of it, written 
by the late Dr. C. V. 
Riley, for one of his 
classic reports on the 
Insects of Missouri: — 
" The larvae of the au- 
tumnal brood," writes 
Dr. Riley, ''when about 
one-fourth or one-third 
grown, build for them- 
selves curious little 
houses, in which they 
pass the winter. First 
and foremost — with 
wise forethought and 




being 
through 



a w are 
natural 



Fig. 23. — Viceroy Butterfly, Back View. 



we 1 
its 
instincts that the leaf 
which it has selected 
for its house will fall to 
the ground when the cold weather sets in, unless it takes 
measures to prevent this — the larva fastens the stem of 
the leaf with silken cables securely to the twig from 
which it grows. It then gnaws off the blade of the leaf 
at its tip end, leaving little else but the midrib. Finally, 
it rolls the remaining part of the blade of the leaf into a 
cylinder, sewing the edges together with silk. The basal 

18 



The Viceroy Butterfly. 

portion of the cyhnder is, of course, tapered to a point, 
as the edges of the leaf are merely drawn together, not 
overlapped ; and invariably the lower side of the leaf 
forms the outside of the house, so as to have the project- 
ing midrib out of the way of the larva, as it reposes 
snugly in the inside. The whole, when finished, has 
somewhat the appearance of the leaf of a miniature 
pitcher plant {Sarracenia), its length being .50-65 inch 
and its diameter .11-14 inch. 

" These curious little cases may be commonly found 
upon our willows and poplars in the winter time. I have 




riG. 24. — Caterpillar resting on Hibernacing Case. 

examined hundreds of them, and although they are inva- 
riably built upon the same plan, they vary greatly in 
the degree of perfection which the architect attained ; 
and this is especially the case where they have been 
built in confinement. The blade on the tip piece is 
sometimes gnawed off right down to the rib ; at others 
it is left almost as broad as the tube. Sometimes it is 
bent over the orifice ; at others not. They are also 
much more irregular and ungainly when made with 
broad leaves, such as those of the silver poplar, than when 
made from the more narrow leaves of the willow. These 
autumnal larvae have also another peculiar habit ; they ex- 
hibit a tendency to build from the time they are hatched, 
and will always eat the leaves from the side, gnawing large 

19 



Nature Biographies. 



holes and cutting along the sides of the midrib. They 
commence at the tip, and as they work downward toward 
the base, they collect the debris into a little bunch, which 
they fasten with silk to the midrib. When the hiber- 
naculum is finished, the seam is perfectly smooth, and the 

whole inside is lined wdth silk. 
The larva having completed its 
work, composes itself for the win- 
ter, with the hind end toward the 
orifice. Here it remains till the 
catkins are in bloom the next 
spring, when it retreats from its 
house and commences feeding. 
Not the least wonderful part of 
the phenomenon is that it is only 
the autumnal brood of larvae that 
form pitcher-like houses to live in 
during the inclement season of 
the year, the summer brood hav- 
ing no occasion to shelter them- 
selves from cold." 

Another interesting thing about 
these cases, pictures of which may 
be seen on page 1 1 and in Figure 
24, is that in the north, they are 
nearly always made near the 
ground, where they are commonly 
protected by the snow during a large part of the winter. 
The caterpillars in spring feed upon the catkins of 
the willow or the poplar, a fact that probably helps to 
limit the food-plants to these two genera. They utilize 
the winter home as a resting-place during the day, and 
the habit of retiring to them is continued long after 

20 




Fig. 25. — The Empty Chrysalis. 



The Viceroy Caterpillar. 

the catkins have given place to the leaves. The charac- 
teristic position assumed, with the head end bent down- 
ward, is shown in Figure 24. 

After a few weeks of feeding in the spring, the cater- 
pillars transform to chrysalids, and soon change again to 
butterflies, thus completing the yearly cycle of the 
species. 



THE AMERICAN TENT CATERPILLAR. 



i 



One of the best examples of a tent-making 
insect is to be found in the common 
American Tent Caterpihar^ of the orchard 
and highway. In July the eggs of this in- 



J 



sect are laid 
in masses of 
two hundred 
or more, which more or 
less completely encircle the 
twigs of apple and wild 
cherry trees (Fig. 26). They 
remain unhatched until 
early the following spring; 
then the tiny caterpillars 
o^naw holes in the eo-o'-shells 
and crawl out. When they 
first emero^e thev huddle 
together on the empty ^^g 
mass, often covering it with 
a slight silken web, as shown 
in Figure 27. They may 




Fig. 26. — Egg Mass of Tent Caterpillar, 



remain here for some days, ^vith slight Web on Left side. 

in which case they produce 

a noticeable tent (Fig. 28) enclosing the ^^^ mass; but 
generally they soon migrate to a near-by fork in the twig. 
From the time of hatching they spin wherever they go a 

1 Clisiocanipa ainericaua Harris. 
22 



The American Tent Caterpillar. 



silken web. When they have congregated on the forked 
twig they spin a web over as well as under themselveSj 
and this web thus becomes a 
sheltering tent. The colony 
of small caterpillars busily 




Fig. 27. 



Egg Mass with More Web 
over it. 



Fig. 28. — Miniature Tent enclos- 
ing Egg-ring. 



spinning the threads of the tent is illustrated in Fig- 
ure 29. 

From the shelter tent they have thus provided, the 
caterpillars march along the twig to the unfolding leaves. 
Upon these they feed, returning to shelter again when 
hunger is satisfied. To go out and come in, the little 

23 



Nature Biographies. 



architects have left one or more openings which serve 
as doorways. They remain within the tent at night, and 
much of the time in rainy weather. New layers of silk 
are added to the outside of the tent as the days go by. 

It commonly hap- 
pens that the first tent 
IS made near the end 
of the branch in the 
fork of a small twig. 
In such cases the food 
supply beyond the tent 
is soon exhausted, and 
it is difficult to enlarge 
the shelter, because 
there are but the two 
branches to build it 
upon. Consequently, 
it can only be a flat 
tent, with little room 
inside. 

To avoid these diffi- 
culties the caterpillars, 
as they grow larger, 
often migrate down the 
limb to a place where 
three or more branches 
go off in various directions. Here a new and more 
commodious tent is built, doors being left in suitable 
places. This home now becomes the centre of a new 
area of leaf destruction as the caterpillars crawl along 
the various branches to feed upon the foliage. 

The most critical periods in the lives of caterpillars 
are the moulting periods. The insects are then sluggish 

24 




Fig. 29. — Young Colony of Tent Caterpillars. 



The American Tent Caterpillar. 



and unable to defend themselves by wriggle or flight. 
Of course these tent caterpillars utilize their shelter 
during these danger- 
ous days, so that on 
the inside of a large 
tent you may always 
find the cast skins of 
the different moults 
that the larvze have 
passed through. 

As the caterpillars 
g-Q back and forth 
from shelter to food 
and from food to 
shelter, they travel 
along the same paths 
day after day. As 
each crawls, it spins 
the ever-present 
thread — perhaps 
originally designed to 
guide it back to the 
nest. The addition 
of thread to thread 
along the route soon 
develops a distinct 
white ribbon of silk, 
which marks the 
pathway, and serves 
as a foothold to the 
marching larvae. In trees having large colonies of cater- 
pillars, these silken bands along the trunks and branches 
become very conspicuous. 

25 




Fig. 30. — A Terminal Tent on Two Branches. 



Nature Biographies. 



It is an interesting sight to see these caterpillars at 
work adding new layers to the nest. A considerable 
number of them assist in the operation, some on the 

outside, others 
just inside the 
outer 1 a }• e r. 
Thev walk rap- 
idly back and 
forth, spinning 
as they go the 
silken thread. 
Each of the 
catei-pillars on 
the outside may 
be seen attach- 
ing the end of 
its thread to the 
bark of the twig 
at one end of its 
line of march, 
then promptly 
turning and re- 
peating the ac- 
tion at the other 
end. They are 
careful not to 
carry silk across 
the openings of 
the doors and thus to close them. Sometimes these 
openings are at the top of the tent, as in Figures 32 and 
33 : sometimes they are at the bottom, as in Figure 31. 

In about six weeks from the time of hatchinor the cater- 
pillars become full grown. Each is then nearly two 




The American Tent Caterpillar. 



inches long, \\-ith a hair}- body ornamented bv a distinct 
white stripe along the middle of the back, on each side 
of which are numerous short yellow, longitudinal lines, 
rather irregularly arranged. The sides are partially 
covered with paler 
lines, spotted and 
streaked with blue, 
while the lower sur- 
face of the body is 
black: the general 
appearance is rep- 
resented in Figures 
34 and 35. 

Sometimes two 
or three colonies 
of the nearly full- 
grown caterpillars 
will unite in making 
a large tent at the 
base of the lower 
limbs of a tree. 
Such multiple colo- 
nies result from the 
fact that the nests 
higher up have not 
room enouo:h to ac- 

commodate the caterpillars as they approach the full 
size. So each colony migrates down the limb to build 
a nest in more commodious quarters. As one colony 
migrates down one limb, another may be coming down 
another limb, and the two combine to build at the base. 
Of course it would rarely happen that these colonies 
would thus moye at exactly the same time, but the result 







Nature Biographies. 



would be practically the same if they came at nearly the 
same time. 

The tent, whether made by one colony or more, is too 
small for all the caterpillars to remain in it and spin their 

cocoons. Most of 
them crawl down 
the trunk of the 
tree and wander 
over the ground, 
seeking a safe 
shelter for the next 
stage of existence. 
When they find a 
satisfactory situa- 
tion — such as the 
under side of a 
board, beneath 
loose bark, or in 
the cracks of a 
fence — each spins 
an oval silken cc- 
coon within which 
its body becomes 
short and thick 
(Fig. 36) before it 
changes to the 
quiet pupa state. 
Two or three weeks later it emerges as a brown moth. 
The appearance of the male tent caterpillar-moth is 
shown on page 22. The males are considerably smaller 
than the females. These moths are nocturnal, tlying 
only at night, and are to be found throughout the greater 
part of July. The females deposit the eggs upon the 

28 




tiG. 33. — Flat Tent with Caterpillars entering Upper 
Door at the Right. 



The American Tent Caterpillar. 



eggs remain 



twigs of trees, and soon die. As already stated, these 
unhatched until the following spring, 
• W'-' '\ aF-^' although tlie tiny 
caterpillars are fully 
formed within the 
egg-shells long be- 
fore the advent of 
winter. 

Now let us con- 
sider for a moment 
what advantages the 
possession of the 
tent gives the cater- 
pillars. Do they 




Fig. 34. 



■Tent Caterpillars at Rest on 
Tent. 




derive substantial benefit from it, 
or is it merely a useless device ? 

To answer these questions we 
should consider the lives of the 
caterpillars in at least three rela- 
tions, namely: first, their relation 
to cold ; second, their relation to 
rain or snow; third, their rela- 
tion to insect and vertebrate enemies, especially birds. 

The relation of tent caterpillars to cold is an impor- 
tant one. Entomologists who rear caterpillars know that 
in warm weather they grow rapidly, while during cold 

29 



35. — Full-grown Cater- 
pillar on Tent. 



Nature Biographies. 




Fig. 36. — Caterpillar shortened for 
Pupation. 



spells they grow little, or not at all. Now the animal 

heat in two or three hundred caterpillars is considerable, 

and if it can be confined to a 

limited space, it must make 

quite a difference in the tem- 
perature as it is felt by the 

larvae t h e m s e 1 v e s. These 

caterpillars develop during a 

period when the nights are 

commonly cold and the days 

are often damp and chilly. They hatch in early spring, 

generally as soon as the first leaves of the earliest trees 

begin to expand, and be- 
come almost or quite full 
grown by the first of June. 
It seems probable that the 
tent is of decided value in 
preventing radiation of ani- 
mal heat from within and 
the entrance of atmospheric 
cold from without, thus in- 
creasing the temperature in 
which the larvae live. 

That these caterpillars 
are sensitive to heat and 
cold is shown by the way 
in which they congregate 
on the outside of the nests 
durino; the warmer hours 
of bright days. One may 
often see large numbers of 

them thus taking their sun-baths. 

The Am.erican tent caterpillars feed normally upon 

30 




Fig. 37. 



Tent where Several Branches 
fork. 



The American Tent Caterpillar. 

the leaves of apple and wild cherry trees. These are 
two of the earliest trees to push out foliage in the spring. 
The closely related Forest Tent Caterpillar — which 
does not make so complete a shelter tent — feeds generally 
upon oak and maple leaves which are comparatively late 
in pushing out. The caterpillars of the latter species 




Fig. 38. — Caterpillars enjoying a Sun-bath. 

are correspondingly late in hatching. So there is a good 
reason why the apple and wild cherry caterpillars are in 
greater need of a shelter tent than are the others. 

The relation of these caterpillars to storms is also 
important. In the spring of 1898, just after the cater- 
pillars had hatched, and before they had time to build 
their tents, there was in central New^ England a heavy 
and long-continued rain-storm. Directly afterward I ex- 
amined a considerable number of tent caterpillar colonies 

31 



Nature Biographies. 

and found that the only survivors were those congregated 
on the under sides of the egg masses, where they were not 
subjected to the washing effects of the rain. The destruc- 
tion of caterpillar life during the storm had been enormous. 
Just such storms are common in April and May: unless 
the shelter tent protected them, the caterpillars would be 




Fig. 39 



Fic;. 40. — Tent raided by Birds. 



constantly exposed to the danger of being washed away. 
And even a well-developed tent does not always protect 
them from hail-storms : Figure 39 shows the havoc such 
storms cause. 

In wdiat ways does the shelter tent protect this cater- 
pillar from its host of living enemies ? It greatly re- 
duces the period of exposure to the attacks of predaceous 
beetles: some of the larger species of these — notably 

32 



The American Tent Caterpillar. 



the caterpillar hunters of the genus Calosoma — would 
be likely to devour any caterpillars which they came 
across in their wanderings, but they would not be likely 
to enter the tent for them. It also prevents, to a consid- 
erable extent, the attacks of many birds, although not all 
of them. And it makes the attacks of wasps and para- 
sites more difficult during the moulting periods. 

But the tent is by no means a comi^lete safecruard 

r 



against all 



enemies. 
Some birds, like the 
cuckoos and the Bal- 
timore oriole, have 
learned to make holes 
in the web, and to tear 
out the larvcc concealed 
within, while some ich- 
neumon flies appear to 
have learned how to 
enter the nest for the 
purpose of depositing 
their eggs. 

It has just been said 
that the Baltimore ori- 




FiG. 41. — Caterpillars killed by Disease. 



ole and the cuckoos feed upon these larv^. In Figure 
40 a nest is shown in which holes have been made by 
one of these birds for the purpose of extracting the cat- 
erpillars. The orioles are more likely simply to pierce 
the skin of the caterpillar and to extract some of the body 
contents, while the cuckoos swallow the insect whole. 
In the stomach of the black-billed cuckoo dozens of 
these caterpillars have been found. 

This difference in manner of feeding may help to 
determine whether a ^ 

33 



given caterpillar's nest has been 



Nature Biographies. 



raided by oriole or cuckoo. If there are many dead and 
mutilated larv^ on the branches near the tent, it was 
probably an oriole. If the caterpillars are gone, and 
there are no such remains, it was probably a cuckoo. 

There is one sort of danger, however, to which the 
colonial lives of these tent caterpillars render them pe- 
culiarly liable. This is the ravages of bacterial diseases. 

These diseases 
I attack many 

insects, espe- 
cially caterpil- 
lars. They are 
very c o n t a- 
gious, so that if 
one larva in 
the colony be- 
comes infected, 
the others are 
likely to suffer, 
because in the 
crowded quar- 
the eerms shall 




P'lG. 42. — Caterpillar, showing Effect of Disease. 

tent it is inevitable that 



ters of the _ 

spread. 

That this is no imaginary danger is shown by many 
observations. In New England, in 1898, there was a 
culmination of an outbreak of the orchard tent caterpillar 
that had lasted many years. The chief agency in reduc- 
ing the outbreak was a disease which appeared during 
damp weather in May and early m June, and killed nearly 
all of the larvae. On every tent the dead and decaying 
larvae could be seen by scores (Figo 41), and as a result, 
there were very few nests to be seen in 1899. 



34 




A RURAL IMPOSTOR. 

In tropical countries, as every one 
knows, there are many insects that 
mimic their surroundings. Won- 
derful tales are told by travellers 
of cunning creatures which so 
closely resemble leaf or twig or 
bark, that it is impossible to dis- 
tinguish them. But it is less 
generally known that in our own 
fields and woods there are many 
examples of such mimicry fully as 
wonderful as those of the tropics. In this brief sketch 
1 wish to bring to light one such impostor. 

Over a large part of the eastern region of the United 
States, the fields and roadsides are overrun by the sweet 
fern, a low-growing shrub familiar to every one who has 
rambled through a New England pasture. It is a vagrant 
plant, not at all choice as to its habitation, speedily tak- 
ing possession of any unused land. It serves as host — 
presumably an unwilling one — to quite a list of insects 
that find good feeding grounds upon its leaves. One of 
the most interesting of these is a strange caterpillar — 
a caterpillar in disguise, for it is strikingly different from 
its kindred. 

Now caterpillars in general are smooth and cylindrical 
creatures, having well-rounded bodies, although many 
of them are clothed with hairs to avoid tempting the 

35 



Nature Biographies. 

greedy appetites of birds. But this insect is in effect at 
least a sweet fern leaf, and a sweet fern leaf has a very 
different appearance from that of an ordinary caterpillar. 
The leaf is long and narrow, with many pointed teeth 
along each side the midrib, and of a dull green or brown- 
ish colour, commonly having a rusty appearance. These 




Fig. 43. — Sweet Fern Caterpillar at Rest. (On lower side, near middle.) 



peculiarities the caterpillar has copied so successfully 
that your chances of finding one of the larvae by search- 
ing the sweet fern branches in the field are considerably 
less than those of the person who hunts for a needle in 
the proverbial haymow. Even on a small branch on 
w^hich you know^ the specimen is resting, it requires sharp 
eyes to see it. It is one of Nature's puzzle problems in 
which you are to find the caterpillar. 

When you succeed in distinguishing the insect from 

36 



A Rural Impostor. 

the surrounding leaves, you should examine it closely to 
see in what ways this remarkable resemblance has been 
brought about. The first thing you are likely to notice 
is that each of the rings of which the body is made up, 
instead of being round in outline as in other caterpillars, 
is nearly triangular in cross-section. On each side of 
the median line the back of the ring has been developed 
into a pointed projection of the form of one tooth of the 
serrate sweet fern leaf. The repetition of these projec- 
tions along the whole length of the caterpillar's body 
has rendered the resemblance to the leaf, as a whole, very 
striking. You will notice also that the head is small 
and angular, making a suggestive tip to the counterfeit 
leaf, while the under side of the body is flattened, and the 
legs are inconspicuous. 

The colour of the caterpillar also helps it out in its 
mimicry of the leaf. The foliage of the sweet fern is 
dull green or light rusty brown, there being nearly 
always many leaves of the latter hue upon the plant. 
The caterpillar is generally of this brownish colour, al- 
though the precise tint varies considerably. 

If these sham leaves were constantly moving about, 
their shape and their colour would profit them little. 
For birds know that true leaves do not wander from 
place to place upon a plant, and a bird seeing such a 
wanderer would be likely to peck at it to see what it is 
made of. Now to a caterpillar a peck is as bad as a 
swallow : if its skin is pierced, its day's work is done. So 
you will find when you keep your caterpillar under obser- 
vation that it will assume a certain position and remain 
rigid and quiet by the hour, apparently sleeping through 
the day. After the friendly shades of night have fallen, 
it will probably wander about and feed freely upon the 

37 



Nature Biographies. 



r^Nsr 



# 



foliage, for then it is safe from observation by the eager 
eyes of birds. But when day returns, it will again be- 
come quiet. 

The position commonly assumed by this caterpillar 
is to take hold of the stem with the pair of feet at its 
posterior end, and to hold the body rigidly out at the 
same angle that the leaves make in their attachment to 
the stems. Very often this position involves such a 
resistance to the force of gravity that you wonder how 

the insect keeps its 
front end in position 
for so long a time. 
If you look carefully, 
however, with a lens 
or reading-glass, you 
can see a silken 
thread extending 
from the mouth to the 
twig; this is the secret 
of the fixed position, 
for this thread holds 
the head in place. 
How did this wonderful adaptation come about .^^ Not 
so very long ago the answer would have been that the 
Creator made the caterpillar so, in order that it might 
escape from its enemies, and additional strength would 
thus be given to the famous argument from design. 
Now, however, we simply cite it as another instance 
of the strange results of the centuries of struggle for 
existence through which the species has passed. In so 
doing we by no means deny that the Creator made the 
insect as we see it, but we simply say that the method 
of its perfection has been through the action of the 

38 




Fig. 44. — Sweet Fern Caterpillar. (On the rij^ht- 
hand vertical leaf, but practically indistinguish- 
able.) 



A Rural Impostor. 

laws of natural selection. For the mystery of life is as 
inscrutable as ever ; we are merely learning, step by step, 
a little about the ways in which it manifests itself. 

When the caterpillar becomes full grown, it makes a 
cocoon from the leaves surrounding it, fastening them 
together by silken threads. Within this, it changes to 
a pupa, to change again later to a beautiful little green 
moth, which is called by entomologists A p lodes rubi- 
frontalia. It belongs to the large and interesting fam- 
ily of geometers — the Geometridse, or Phalaenidae. 



39 




A DEVASTATOR OF FORESTS. 

'^ It is comparatively seldom that man has 
an opportunity to learn what would hap- 
pen if, so far as forests and their enemies 
w^ere concerned, the delicately adjusted 
" balance of nature " did not exist, so that 
tree-feeding insects had free opportunity 
to increase to the limits of their food sup- 
ply. Probably when the good people of 
Massachusetts let the Gypsy Moth Cater- 
pillars spread over the land, opportunities 
of this sort will not be so lacking as in the past and at 
present. Occasionally, however, a species gets beyond 
the control of its natural enemies even now, and is able 
to work its will upon the forests, apparently unchecked 
by any agencies. A notable instance of this kind was 
the recent outbreak of the forest tent caterpillar^ in New 
England and New York, during wiiich thousands of acres 
of woodlands were defoliated, and an immense number of 
valuable trees w^ere destroyed. Maple woods were espe- 
cially affected, but nearly all sorts of deciduous trees 
were also attacked. 

These forest tent caterpillars pass the winter within 
the egg-shells, the eggs having been deposited the 
previous summer in cylindrical masses that form com- 
plete circles upon the smaller twigs of a considerable 
variety of trees. The eggs are covered with a brittle 

1 Clisiocajjipa dis stria. 
40 



A Devastator of Forests. 



substance which gives the egg mass a shiny appearance, 
brie lit 



especially in a briglit Hght. The general shape of 
the '' caterpillar belt," as it is called in some localities, is 
shown in Figure 45, the length of the belt varying from 
one-fourth to one-half of an inch; the diameter is usually 
one-fourth of an inch. The belt 
terminates abruptly at each end, 
although it is not as a rule 
squared off. The outside of 
the belt consists of a glistening, 
varnish-like, brownish or lead- 
gray material, which covers the 
eggs. When the eggs are first 
laid, and for some months after- 
ward, this covering remains en- 
tire, but as the winter passes it 
becomes more and more broken, 
so that by spring it generally 
has a rather ragged appearance. 
By removing the covering the 
eggs will be found beneath, 
resting side by side at right 
angles to the supporting twig 
<Fig. 46). Each egg is a trifle 
longer than wide, and is covered 
with a reticulated network of 
the same varnish-like material that conceals the mass as 
a whole ; this network serves to attach the eggs to the 
twig, and to each other. The eggs are of a dull gray 
colour, showing white in some places. When the cater- 
pillars hatch they gnaw off a circular cap on the upper 
end of the shell, and come out through the hole thus 
made. Each egg is about one-twentieth of an inch long. 

41 




Fig. 45. — Egg Mass of Forest Tent 
Caterpillar. 



Nature Biographies. 



The number of eggs in one beU varies from less than 
150 to more than 225, the average being nearly 200. 
When the insects are so abundant that there is a partial 
exhaustion of the food supply of the caterpillars, the 
normal number of eggs are not laid, the egg-rings being 
much smaller than usual. 

These egg masses are deposited in July, and remain 
un hatched until the following spring. The actual forma- 
tion of the tiny caterpillars from the 
contents of the Qgg takes place, how- 
ever, within a few weeks after they 
are laid. By a careful examination, 
the minute but fully formed larvae 
may be found within the egg-shells 
any time between September and the 
following April. The caterpillars re- 
main during this long period quietly 
confined within their narrow houses, 
but when the warm rays of the spring 
sun penetrate their abodes, they eat 
off the tops of the egg-shells, and 
come out ready to break their long 
fast upon the tender foliage of the ex- 
panding buds. They are then tiny 
creatures, scarcely one-tenth of an inch long, showing 
under a lens that the blackish body is thickly covered 
with rather long brownish, or grayish, hairs. They feed 
upon the unfolding leaves of the twig near where the egg 
mass was placed. In about two weeks each increases in 
size to such extent that the skin in which it came from 
the egg is too small for it. This skin then splits open 
along the back, and the caterpillar crawls out, clad in a 
new skin that had gradually been forming beneath the 

42 




Fig. 46. — Egg Mass, 
with Outer Covering 
removed. 



A Devastator of F'orests. 

old one. This skin-shedding process is called moulting: 
it is the general way in which insects pro\'ide for in- 
crease in size. 

The caterpillars very commonly emerge from the eggs 
some time before the leaves of their food-plants push 
out. Under such conditions the tiny larvae are likely to 
huddle together upon or near the egg mass to await the 
unfolding of the leaves. There seems to be considerable 
variation in the time of hatchino-, as larv^ of various 




Fig. 47. — Miniature Tent with Cast Skins. 

sizes may be found at any time during the latter part 
of May or in June. 

Wherever they go, these little larv^ spin a silken 
thread which marks their pathway, although the thread 
is so slender that a single one is generally to be seen 
only through a lens, but in places where the larvc'e con- 
gregate to rest when not feeding, a habit that they have, 
it becomes quite noticeable. It is especially so after 
moulting, for then one can often find on the end of a 
forked twig such a miniature tent as is represented in 
Figure 47, the cast skins being intermingled with the 
silken threads. 

Soon after the first moult the caterpillars begin feed- 

43 



Nature Biographies. 



ing again, eating, of course, more and more of the fohage 
as they become larger. A week or so later they again 
moult, a process which is repeated twice, thereafter, at 
similar intervals. At the time of the later moults, the 
caterpillars are in the habit of congregating upon the 
trunks or larger limbs of the tree, often not far from 

the ground. Beneath the 
mass of larvae there is an 
inconspicuous web, in which 
the feet are more or less 
entangled. The appearance 
of the caterpillars at such 
times is well shown in the 
photograph reproduced in 
Figure 50. At the end of 
about five weeks from the 
time of hatching from the 
egg, the forest tent caterpil- 
lars become full grown in 
this, their larval state. Each 
is now about two inches long 
and one-fourth of an inch 
thick. It is cylindrical in 
shape, with six jointed legs 
arranged in pairs directly back 
of the head, eight thick pro- 
legs along the middle, and two prolegs at the hind end 
of the body. The head is dark bluish, and the body in 
general has a bluish appearance, more or less modified 
by the longitudinal series of marks and stripes. Along 
the middle of the back there is a series of whitish or 
cream-coloured marks of the shape shown in the picture 
on page 45. Along the upper part of each side there is 

44 




Fig. 48. — Another Tent with Cast 
Skins. 



A Devastator of Forests. 



a broad blue stripe, bordered above and below by a nar- 
row, irregular, yellowish white line. On the lower sur- 




FiG. 49. — Cast Skins 
on Branch. 



Fig. 50. — Caterpillars resting upon a Branch. 



face the colour is bluish black. The whole body is 
sparsely clothed with rather short hairs. 

These full-grown caterpillars are now ready to enter 
upon the next stage of their existence, that of the pupa, 
or chrysalis. This is a quiet stage, in which the insect 

45 



Nature Biographies. 



takes no food, and is unable to move about, and it needs 
to protect itself from its various enemies. Consequently, 
each caterpillar spins from certain silk glands in the 
mouth a shroud of silken threads, surrounding itself by 
an oval cocoon composed of several layers of silk, the 
outer ones much looser than the inner, with the hairs of 
the caterpillar intermingled with the silk on the inside 

layers. When this cocoon 
is first spun it is white, but 
the caterpillar soon colours 
it yellow wdth an excretion 
from the body. 

The caterpillars generally 
prefer some sort of frame- 
work to build their cocoons 
upon. They commonly 

choose the leaves of trees 
for this purpose. Some- 
times a single large leaf wall 
be used, its edges being 
folded over, as in the case 
of the cocoons in apple and 
currant leaves, shown in 
Figures 51 and 52; while 
at others, several smaller 
leaves may be deftly drawn together, as in the bar- 
berry leaf cocoon shown in Figure 53. If the insect 
happens to be in a pine tree, it will utilize the pine nee- 
dles for this purpose, and even such delicate structures 
as the panicles of the smoke bush or fringe tree may 
serve the purpose. Where the catei*pillars are numer- 
ous, the foliage of the trees is almost wholly webbed up 
when the cocoons are made, giving the trees a strange, 

46 




Fig. 51. — Cocoons in Apple Leaves. 



A Devastator of Forests. 



bunchy appearance. Many of the caterpillars, however, 
leave the trees, and seek shelter in other situations, such 
as crevices in the rough 
bark, beneath boards or 
stones upon the ground, in 
the crannies of a fence, 
along the clapboards, or be- 
neath the gables of build- 
ings. 

Wherever the cocoon is 
spun the caterpillar inside of 
it soon changes to a pupa or 
chrysalis — an oval, brown 
object without legs or wings, 
able to move only by a 
feeble wriggle of its body. 
The pupa that is to de- 
velop into a female moth is 
^ slightly 

larger than that of the male. In 
this stage the insect takes no food, 
but its tissues undergo such remark- 
able changes that about ten or twelve 
days after the cocoon is made, a 
buff-brown moth emerges from the 
chrysalis and makes its way through 
one end of the cocoon. This is the 
adult form of the forest tent cater- 
pillar. The male moths are slightly 
smaller than the females, as may be 
seen in Figures 54 and 55, in which 
the two sexes are represented by drawings, natural size. 
The feelers, or antennae, of both sexes are feathery, but 

47 




Fig. 52. — Cocoon in a Currant Leaf. 




Fig. 53. — Cocoon in Bar 
berry Leaves. 



Nature Biographies. 

those of the male are much broader, as well as somewhat 
longer. 

The moths generally make their appearance during 
the latter part of June. Soon afterward the females 
deposit their eggs in masses of about two hundred each 
upon the twigs. The moths, having completed the cycle 
of life, die soon after the eggs are laid. 

As a result of much patient watching, my assistant, 
Mr. W. F. Fiske, was so fortunate as to observe one of 
these moths depositing her eggs. He has recorded his 
observations as follows : — 

"On the afternoon of June 27, three pairs of freshly 
emerged moths were found in the breeding cages mating, 





Fig. 54. — Moth, Male. Fig. 55. — Moth, Female. 

and two of them placed, without separating, under a bell- 
jar with some green twigs of apple. At 8 p.m. one pair 
had separated, and the female was very active, buzzing 
around the interior of the bell-jar. Fifteen minutes later 
she had taken notice of the apple twigs, and was more 
slowly crawling over them. By 9 o'clock she had selected 
a site for an egg-ring, and had just begun its deposition. 
About a dozen eggs were laid at this time, in the form of 
a right triangle, one side forming what was to be one edge 
of the future egg-ring. On what would correspond to 
the hypothenuse of this triangle she was now busy 
depositing more eggs, making each row longer, and 
increasing consequently the width of the future band, 

48 



A Devastator of Forests. 

still keeping the general form of the egg mass the same. 
The placing" of the first Qgg in each row is accomplished 
with some difficulty, and is also a matter of some delicacy, 
for if it is not placed correctly, the whole band may suf- 
fer; but after this is done, the remainder are easily fixed 
in their proper positions, the abdomen, which is stretched 
nearly to its limit, so moving that each egg slips into the 
space between the end egg on the row under construc- 
tion and the corresponding egg in the row just com- 
pleted. The eggs are laid at intervals of about half a 
minute, and after each is deposited there is a second's 
pause, followed by a little pile of bubbles of creamy white- 
ness, which rise around it and help to form the tough, 
protecting winter coat. It is very difficult to get a good 
view of the operation at close hand, on account of the 
position in which the wings of the moth are held, droop- 
ing and well covering the abdomen, and it cannot be 
stated with certainty whether the egg itself is deposited 
just before or just after the extrusion of the froth. 

" The width of the band being decided upon, the rows 
are made of uniform length thereafter, and the girdle 
begins to take form. In the case under observation, as 
the moth was undersized, the band was a narrow one, 
and the number of eggs in each row was about seven. 
When the band was nearly completed, after about an 
hour's work, the moth was disturbed, and for the re- 
maining distance the rows were anything but regular. 
Whether as a result of this break or otherwise, there 
were a lot of eggs left over after the ends of the bands 
were united, and these were deposited slowly and irregu- 
larly, with much preliminary feeling about on the lower 
edge of the band. This part of the operation required 
above an hour, or as long for the placing of a few dozen 

49 



Nature Biographies. 

eggs as it did for the construction of the girdle proper. 
The whole time, from the first observation until the egg 
mass was finally left, was about two and a half hours. 
The moth did not long survive the completion of the 
ring, but within a few hours, before it had been a whole 
day in its perfected form, it died." 

A condition that has been repeatedly noticed during 
the last three years seems to indicate that in general the 
instinct of the moth teaches it to deposit eggs only on 
trees bearing leaves at the time the eggs are laid. When 
a maple orchard is defoliated one year, it is likely to 
escape the next year, unless it is invaded by caterpillars 
hatched on the surrounding trees. The moths that de- 
velop on such a lot of defoliated trees apparently fly to 
the surrounding trees that still bear leaves before deposit- 
ing their eggs. Of course this habit is of advantage to 
the insect, for the chances of a sufiicient food supply for 
the caterpillars are greatly increased by it. In some 
cases, however, the explanation is that the caterpillars 
completed the defoliation of the trees before they were 
full grown, and then migrated to new feeding grounds. 

Like most moths the adults of these forest cater- 
pillars are night-fliers rather than day-fliers. They are 
attracted by light after dark, and frequently fly through 
open windows into houses. Late in the afternoon they 
may also be seen when abundant, flying among the 
branches of the trees. 

When the caterpillars are disturbed while feeding upon 
the leaves or crawling along the twigs, they have a habit 
of dropping downward, checking the fall by means of a 
thread spun from the mouth and attached to the twig. 
Thus suspended in mid-air they are very annoying to 
foot-passengers in villages, or to people riding along 

50 



A Devastator of Forests. 



shaded roads in town or country ; for to find yourself 
suddenly confronted by a dozen caterpillars on the level 
•of your face is disconcerting. 

Even when not disturbed by man, a large proportion 
of the caterpillars drop down by means of the thread at 
one time or an- 
other during 
their growth : 
some are prob- 
ably startled 
by the sway- 
ing of the twig 
in the wind ; 
others by birds 
when alight- 
ing ; in many 
cases the 
movement is 
probably in- 
duced by the 
exhaustion of 
the food sup- 
ply, or, per- 
haps, by a 
migratory in- 
stinct. In any 
event, this dropping is very general, and as a result the 
caterpillars are continually to be seen crawling up the 
trunks of the trees ; this is especially likely to be the case 
early in the morning. 

When an orchard, grove, or forest in which these cat- 
erpillars have been feeding, is defoliated, the insects 
migrate to neighbouring trees, in a way suggestive of the 

51 




Fig. 56. 



-Forest Tent Caterpillars at Rest. (Two of the 
American species are also present.) 



Nature Biographies. 

migrations of the army-worm. At such times they often 
appear in incredible numbers. Several cases are on rec- 
ord where in crossing railway tracks they have impeded 
the progress of trains by making the rails slippery as the 
bodies were crushed. One case which has been vouched 
for by the entomologists of the United States Depart- 
ment of Agriculture, after official investigation, is re- 
ported in these words : — 

" The rails on the Carolina Central railroad were cov- 
ered inches deep with caterpillars, so that for three days 
in succession trains were brous^ht to a dead standstill, the 
driving-wheels of the engine slipping round as though the 
rails had been thoroughly oiled. The engineers were 
obliged to exhaust the contents of the sand boxes before 
crossing the strip of swamp from which the caterpillars 
seemed to come. The rails and cross ties were said to 
be obscured from sight, and the ground and swamps on 
each side of the track were covered with millions of the 
crushed catei*pillars, and from the mass an unendurable 
stench arose." 

During recent years there has been considerable dis- 
cussion among the professional entomologists as to the 
best popular name for this insect. Its common name, 
forest tent caterpillar, is not very satisfactory, because 
the insects are as likely to be found in apple orchards as in 
forests, and they do not make tents in the complete sense 
that the nearly related American tent caterpillar does. 
Various substitutes for this name have been recently 
proposed, none of which, how^ever, seem to me sufficiently 
satisfactory to warrant a change. Professor M. V. Sling- 
erland of New York has proposed that the insect be 
called the forest tentless caterpillar ; but the objections 
to this are, first, that it is not absolutely a tentless cater- 

52 




A Devastator of Forests. 

pillar, many of the caterpillars making in early life min- 
iature tents, like the one shown in Figure 47 ; and, second, 
as Dr. L. O. Howard has pointed out, there are a great 
many other tentless caterpillars that feed upon forest 
trees. 

Fortunately for man these forest tent caterpillars are 
preyed upon by many natural enemies, including insects, 
spiders, toads, and birds. Among the more important 
insect enemies are the ta- 
china-flies and the ichneu- 
mon-flies. In the recent 
New England outbreak at 
least three species of Tachi- 
nids ^ were at work destroy- '^ ^ 

.11 , r , "ii Fig. try. — Tachinid Parasite of Forest 

mor the hosts of caterpillars, r^ ^'. , .„ ^ , 

r lent Caterpillar : a,Viy\ /;, puparium. 

One of these flies is repre- 
sented somewhat magnified in Figure 57 ^: it looks much 
like a common house-fly, and is of about the same size. 
This fly deposits a whitish ^^^ upon the skin of the 
caterpillar, generally after it is more than half grown. 
The ^g^ soon develops into a tiny grub that burrows 
through the egg-shell and the skin of the caterpillar into 
the inside of the body. There it remains, absorbing the 
tissues of its host, and gradually increasing in size. In 
due time it becomes fully developed in this grub state, 
and breaks through the skin of the caterpillar. It is 
then a good-sized, white, oval, footless grub. The cater- 
pillar has generally spun its cocoon before the parasite 
comes from its body, so that the parasite finds itself in- 
side the cocoon when it gets outside the caterpillar. 
The grubs of two species of these Tachinid parasites 

1 Tachina mella Walk, Exorista fiitilis O. S., and Frontina frenchii 
Will. 

53 



Nature Biographies. 

work their way through the cocoon and drop to the 
ground, while the other seems to remain in the cocoon. 

The parasitic larvae have now to enter upon the 
quiet pupa stage. For this purpose the outer skin turns 
brown, and becomes hard, forming a protective cover- 
ing for the insect inside. This is called the ptiparmm 
(Fig. 57 b). Within this covering the insect changes 
to a pupa, to change again about two weeks later into 
an adult fly. 

After an outbreak of the forest tent caterpillars has 
continued for two or three years, these Tachinid para- 
sites frequently become very abundant. They are often 
a chief cause for the cessation of an outbreak. In one 
New^ Hampshire town a year or two ago the people saw 
great numbers of strange flies swarming about the fields 
and pastures : they were probably these Tachinids. 

Among the ichneumon-flies, the parasites of the genus 
Pimpla are the most abundant enemies of these caterpil- 
lars. The adult is a four-winged fly that deposits eggs 
in the caterpillars or the newly formed chrysalids after 
the cocoons are spun. Shortly after being laid the eggs 
hatch into minute grubs that develop at the expense of 
the chrysalids, finally eating up nearly all their sub- 
stance. About two weeks after the eggs are laid, the 
parasitic larvae change to pupae, and soon afterward 
again change to adults. 

These caterpillars are also subject to the attack of cer- 
tain bacterial diseases which are often very destructive, 
especially during w^et seasons. And sometimes when 
small they are killed off in enormous numbers, by late 
frosts. 

It has frequently been pointed out that one of the 
greatest services which birds render to man is that of 

54 



A Devastator of Forests. 

concentrating their attack upon outbreaks of injurious 
insects. In this respect they are hke a great standing 
army that, on short notice, can be mobiHzed upon any 
point where danger threatens. Although these forest 
tent caterpillars are protected from many birds by their 
hairy coverings, they furnish a good illustration of the 
value of birds in such emergencies. Careful observa- 
tions upon this phase of the recent outbreak were made 
in Vermont bv Miss Caroline G. Soule, who kindly com- 




Fig. 58. — Cast Skins of Poorest Tent Caterpillar. 

municated to me the results. " A surprising number of 
birds were seen feeding upon the caterpillars, the list 
including robins, orioles, chipping sparrows, cat-birds, 
cuckoos, three species of vireos, cedar-birds, and nut- 
hatches. The latter were particularly useful, as they 
would stand by a patch of larvae, lying close together 
below^ a tar band on a tree, and eat so voraciously, and 
with such an entire abandonment of self-consciousness, 
that I could go close and put my hand on them before 
they would fly. This experience was repeated several 

55 



Nature Biographies. 

times." During the last season that the caterpillars 
were abundant Miss Soule wrote: ''I am almost sure 
the caterpillar has drawn the birds here ; for in four 
summers I have never seen nearly so many as this year, 
though I have been observing birds for years. Too 
much cannot be said for the birds. The orioles and 
the red-winged blackbirds, especially, are stripping the 
trees of pupae. Yesterday I saw orioles at work on a 
beech and an oak that had been badly eaten at the top, 
and I pulled down some of the branches and examined 
each of the many cocoons. Every one had the neat slit 
these birds make, and every pupa was gone. The baby 
orioles all learn to do this as soon as they can fly from 
one tree to another." A little later cedar-birds were 
seen flocking to the trees, opening cocoons and devour- 
ing the pupae. On July 8, Miss Soule wrote, " The 
number of birds is really amazing, and the thorough 
work they do is delightful." 

Regarding the birds that feed upon the moths, the 
same keen observer, in an admirable article in the 
Springfield Republican wrote : " Many cocoons gave 
the moths in July, and these little brown moths could 
be seen in great numbers flying about the maple, elm, 
apple, pear, ash, and other trees, laying their eggs near 
the tips of the twigs, — frying by daylight. Then the birds 
had another feast. Vireos of four kinds, flycatchers of 
three kinds, both cuckoos, robins, rose-breasted gros- 
beaks, tanagers, cedar-birds, cat-birds, orioles, red-winged 
blackbirds, martins, and sparrows fed on the moths as 
they had done on the pup^e and larvae. Chipping spar- 
rows became expert ' lofty tumblers ' in their zigzag pur- 
suit of the flying moths, and even the English sparrows 
had a brief season of usefulness, for they really ate some 

56 



A Devastator of Forests. 

of these moths, though they would not touch either pupae 
or larvae." 

The Baltimore orioles were among the most efficient 
enemies of the caterpillars, destroying them in great 
numbers for their own food as well as to feed their 
young. These orioles are exceedingly useful birds, as 
they generally feed freely upon hairy caterpillars. 



57 



STUDIES OF WALKING-STICKS. 



% 




The Walking-stick ^ has always 

seemed to me to occupy among 

our insects much the same posi- 

^ ' ^ tion that the least bittern occupies 

'^ - ^ amono- our birds. The latter has 

been well described bv Mr. Frank 
M. Chapman as '' a half -solved 
mystery," to be thought of "less 
as a bird than as a survivor of a 
former geological period, when birds still showed traits 
of their not distant reptilian ancestors." Both these 
creatures are extreme examples of that resemblance to 
surroundings which enters so largely into the make-up 
of the animal world, and they both have a well-developed 
instinct for keeping quiet to render more effective their 
peculiarities of colour and structure. The walking-stick 
seems, indeed, to have stepped from the pages of the 
books of Bates and Wallace with their stories of tropical 
mimicry, or at least to belong exclusively to the fauna 
of our Southern states, where it has for company the 
weird praying mantis. In Puritan New England it 
seems bizarre and out of place. 

During last autumn these walking-sticks were unusu- 
ally abundant in southern New Hampshire, and I took 
advantage of the fact to get some pictures. Better sitters 

^ Diapheromera femorata Say. 

S8 



Studies of Walkings-sticks. 



one could not ask for: they would remain quiet and " look 
pleasant " by the hour, so that time exposures could be 
made to one s heart's content. They were happy w^ith only 
a bit of birch twig for support, and it seemed a matter 
of entire indifference 
to them whether they 
hung on with three legs 
or six, although they sel- 
dom utilized the latter 
number. A common 
position of the male is 
shown in Figure 60: 
the insect rests head 
downward, with the 
two front legs and the 
antennas closely ap- 
pressed and projecting 
forward as a continua- 
tion of the body. The 
termination of the head 
is not easily distin- 
guished. Another po- 
sition in which the 
front legs are not held 
so closely together is 
shown in Figure 59. 
The body is parallel 
with the twig, and the 
chief support is derived from the two hind and one of 
the middle legs. 

The body of the female walking-stick is considerably 
larger than that of the male, but it attitudinizes in much 
the same way. A back view, in which it is clinging to 

59 




Fig. 59. — Walking-stick, Male, resting with 
Head Downward. 



Nature Biographies. 



the support with its four rear feet and one front one, is 
shown in Figure 6i. As will be seen, the other front leg 
projects forward beside the antennae : on account of the 
larger body, the termination of the head is more plainly 
visible than in the male. Figure 62 shows a side view, 

^ in which five of the legs 
seem to be utilized for 
support, and one held 
out forward along with 
the antenna, one of 
which is curled down 
in an unusual position. 
When one has watched 
these queer creatures 
thus taking on attitudes, 
and holding them by 
the hour, it is interesting 
to study their structure 
to see in what ways they 
are adapted to their curi- 
ous existence. One of 
the most remarkable 
things about them is the 
- entire absence of wings. 
/ith Head Another is the unusual 
development of the tho- 
a little observation through a lens shows distinctly 
the three divisions of the thorax. The prothorax next 
the head is short and bears the second pair of legs 
near the middle of the under surface. The mesothorax 
is very long — the longest segment of the body — and 
bears the second pair of legs at its posterior end. The 
metathorax is a little shorter than the mesothorax and 

60 




Fig. 60. — Walking-stick, Male, 
Downward. 



rax 



Studies of Walking-sticks. 



bears the third pair of legs also on its posterior end. 
Then follows the abdomen with its nine short joints — all 
together just about equalling in length the three thoracic 
segments. The head seems but a continuation of the 
thorax, except for the large, well-rounded, projecting 
eyes which must give the creature a range of vision 

almost equal to _ 

thatofthe j 

dragon-fly. The 
slender, many- 
jointed antennae 
that project 
straight forward 
from the head 
are four-fifths 
as long as the 
body, and a lit- 
tle longer than 
the slender front 
legs. The latter 
at their 
a distinct 
peculiar 
curve which en- 
ables the insect 
to bring them 

close together in front of the head; this curve may be 
seen in Figure 6i. 

The middle legs are shorter and more robust, while 
the hind ones again are slender and nearly as long as 
the front ones. All the legs are so attached to the body 
that the first long joint extends sideways, and can even 
be bent upward at an acute angle. The legs are loosely 

6i 



show 

base 

and 




Fig. 6i. — Walking-stick, Female, Back View, 



Nature Biographies. 



jointed, so that in the hving insect the members of the 
same pair are seldom symmetrically arranged (Fig. 63). 
This is doubtless an important point, for the insects 
would be much more easily seen upon twigs if the legs 

were held in positions 
of bilateral symmetry. 

The more you look 
at one of these walking- 
sticks the more you are 
impressed with its won- 
derful mimicry of a bit 
of twig. The body sur- 
face has the shine of 
young bark, and minute 
irregularities on parts of 
lis surface help out the 
resemblance. The col- 
our, too, helps to the 
same end : it is a mot- 
tled brown or Qrrayish 
oreen, much like the 
bark of little twigs of 
oak and other trees. 

These walking-sticks 
are vegetarians, feeding 
upon the leaves of oak 
and various other trees. The females drop their eggs 
from the place where they are feeding: a considerable 
number were laid by the specimens in my vivaria, some 
of which are illustrated on page 58. They look like 
little seeds, and as a matter of fact, the part we see 
from the outside is simply a little capsule inside of which 
is the egg proper. Out of doors these eggs remain 

62 




Fig. 62. — Walking-stick, Female, Side View, 



Studies of Walking-sticks. 



upon the ground until tliey hatch the following spring, 
although it is said that sometimes part of them live 
over two winters before 



hatchino-. 

o 

During 



ight 



walking sticks 



day 
these 

must be in constant 
danger of execution 
by birds, and presum- 
ably it is to escape 
such danger that they 
rest so quietly in one 
position for hours at a 
time. They are said 
also to fall victims to 
certain predaceous 
bugs that wander over 
trees and shrubs in 
search of caterpillars 
and other insects 
whose life-blood they 
may suck. 




Fig. 63. — A Pair of Walking-sticks upon a 
Birch Twig. 



63 



THE CHOKE-CHERRY TENT-MAKER. 




The two species of tent caterpillars 
already discussed are often cited as 
examples of insects that spend an 
extraordinarily long period in the 
condition of the eo-^;. With these 
species the eggs deposited in July 
do not hatch until the followino- 
April, so that nine months out of 
the twelve are thus passed. Were 
our know^ledge of the insect world . 
sufBciently complete, we should 
probably find many other similar 
examples. Even with the com- 
parative ignorance of the present, 
such a one occasionally comes to 
light. One of the most interest- 
ing of the recently discovered ex- 
amples of this is the case of the 
Choke-cherry Tent-maker, an in- 
sect that frequently becomes very 
conspicuous in early summer, on 
account of the pointed tents that 
it makes along fences and high- 
ways, and by the borders of the 
woods — wherever, in fact, the 
ubiquitous choke-cherry sends up 
its branches. 

The first indication that one 

64 




Fig. 64. — Early Stage of Tent. 



The Choke-cherry Tent-maker. 



commonly sees of the presence of these insects is the 
webhing together, early in spring, of two or three of 
the terminal leaves of the small cherry bushes. These 
webbed leaves are not at all conspicuous, resembling at 
first the normal unfolding leaves at the tip of the twig. 
If you open them 
up, however, you 
will find inside a 
o^reat number of 
tiny whitish larvae, 
which will be dis- 
turbed by the un- 
usual conditions 
as to light, and will 
rapidly escape. 

When you have 
thus found a 
young colony of 
these tent-makers, 
you will wonder 
where they came 
from. It seems 
probable that they 
recently hatched 
from eggs, but if 
you look carefully over the adjacent parts of the twig, 
you will be unable to find any indications of the egg- 
shells. In the case of some butterflies that deposit their 
eggs singly, the caterpillar on hatching eats up the 
empty egg-shell — so that no hungry enemy may discover 
that a young caterpillar is in the vicinity. But so far as 
I know this method is not adopted by the larv^ that live 
in colonies, so it seems improbable the egg-shells could 

65 




P^iG. 65. — A little Later Stage of Tent. 



Nature Biographies. 



have been eaten by the tiny creatures that you find 
within the roHed leaves. The only thing to do is to 
extend your search farther afield : continue to examine 
the bark carefully from the tip of the twig toward the 
base, and just before you reach the ground, if your eyes 
are sharp, you will find what appears to be a bit of bark 
with a lot of little holes in it; it is slightly raised above 

the surrounding 
surface, although 
of nearly or quite 
the same colour. 
Through a lens 
you will readily see 
that this is an ^gg 
mass from which 
the larvae have 
hatched. You can 
but marvel at the 
perfect adaptation 
shown by these 
eo^o's to the condi- 
tions of their life : 
were they on the 
upper part of the branch, many of the masses would 
be found by the eager eyes of birds, notwithstanding 
their resemblance to the bark; but down by the ground 
there is a bit of surface which is not so generally 
inspected by the birds, and this is where the eggs are 
placed. 

In spring, when the leaves of the cherry bushes have 
pushed out, the eggs hatch into tiny larvae that instinc- 
tively crawl up to the top of the branch, where they 
ensconce themselves within the unfolding leaves, sewing 

66 




Fig. 66. — A completely enclosed Tent. 



The Choke-cherry Tent-maker. 



their edges together by means of the silken threads that 
apparently are available from the time of hatching. They 
feed upon the succulent tissues of the shelter they thus 
construct, and within 
which they are to 
remain for the next 
few weeks. New 
leaves are added to 
the webbed mass 
from day to day, 
and before long the 
larvae are able ^to 
bend good-sized 
twigs to their pur- 
pose, as seen in 
Figure 67, which 
also shows the way 
in which the leaves 
are eaten on the 
edge just inside 
the web. As fast 
as the leaves are 
eaten new twigs are 
webbed over and 
brought into posi- 
tion (Fig. 68), the 
tops being brought 
together in such a 

way as to form at last a veritable conical tent, a com- 
mon form of which is shown in Figure 69. The silken 
threads must have remarkable streno^th to web and 
hold together the good-sized twigs that are often thus 
enclosed. 

67 




Fig. 67,- 



■Tent showing the Way in which the 
Leaves are eaten. 



Nature Biographies. 



Within this tent the larvse pass their Kves, gathering 
together toward the middle during the day, when they 
are not feeding, and enlarging the tent and feeding 
toward dusk or after dark. They moult from time to 
time as their growth requires, keeping well within shelter 

at these critical periods. 
If the food supply of 
the original bush be- 
comes exhausted, the 
larvae web up the sur- 
rounding grass and 
herbage ; probably in 
search for another 
cherry bush. If one 
be found, they take 
possession of it. Each 
original colony com- 
monly consists of a 
great number of larvae, 
— probably more than 
a h u n d r e d, — and 
neighbouring colonies 
appear often to join 
forces in the operation 
of tent-making, especially after this wandering for food 
begins. 

These tent-making larva? are rather slender, naked,, 
whitish, wormlike caterpillars, without conspicuous mark- 
ings except the blackish heads. Except for the tent, 
they have no means of protection against birds and 
other enemies. By working on the tent and feeding 
after dark they escape observation by birds, and in part,, 
at least, the attacks of predaceous insects and parasites. 

6S 




-i^^d 



-X 



Fig. 68. — Tent showing Bending of Twigs. 



The Choke-cherry Tent-maker. 



About five or six weeks from the time of hatching, the 
caterpillars become full grown, so far as this larval state 
is concerned. They now retire to the middle of the 
tent, where they unite to form a colony of cocoons side 
by side, the silken threads of the cocoons being more or 
less intermingled with the dried 
particles of excrement. Within 
these cocoons the larvae change 
to pupae, the quiet stage in which 
they rest and take no food. In 
about two weeks the pupse wriggle 
out from the cocoons and reach 
the outer surface of the tent, where 
they hang until the dry outer skin 
of each splits apart and the small 
orange-brown moths emerge. The 
empty pupa skins, as they hang 
from the deserted tent, are shown 
in Figure 70. 

The moths are beautiful little 
creatures. They fly about at 
night, depositing their flattened 
masses of eggs upon the bases 
of the cherry bushes. When first 
laid these masses are distinctly 
yellow, but in course of time 
they lose their brightness, and take on the sombre brown 
of the surrounding bark. After about two weeks of 
winged existence the moths die, and for the next nine 
months the species exists only within these obscure egg 
masses hidden away at the bottom of the cherry bushes. 

If you confine one of the cocoon masses — soon after 
the larvae have pupated — within a glass jar, you will 

69 




Fig. 69. — A Completed Tent. 



■HIB 



Nature Biographies. 

be likely to get a lot of the moths, and in addition quite 
a number of four-winged flies, very different in appear- 
ance from the moths. These 
\ ' '^ are Ichneumon parasites. 

You will notice that many of 
them have long ovipositors 
projecting from the abdomen. 
It was probably by means 
of this organ that the parents 
of these flies were able to 
penetrate the folds of the tent 
and lav their eQ:G:s on or in 
the larvae or pup^ of the 
cherry twig-tiers. 

These moths belong to the 
family of leaf rollers, called 
Tortricidee. It is a large 
family including many in- 
sects that feed upon the 
leaves of trees and other 
plants, most of the larvae liv- 
ino- within the rolled leaves 
of their food-plants. But 
some of them have fovmd 
that other parts of piants 
besides the leaves are edible 
and so have changed their 
habits to take advantage of 
the discovery. The most 

Fk^,. 70. — Emptv Pupa Skins pro- . . , r i • • 

jecting fi-om Tent. famfliar cxamplc ot this is 

the larva of the codling 

moth which is so often found in apples, where it gets its 

food by eating the pulp of the fruit. 

;o 




THE ANTIOPA OR MOURNING-CLOAK 
BUTTERFLY 



During sunny days in spring, 
one may often see a beau- 
tiful purple-black butterfly, 
having a cream-coloured 
border along the outer mar- 
gin of its wings, flying lei- 
surely about, in the vicinity 
of woods and in the open 
fields. This insect is called 
the Antiopa or Mourning- 
cloak Butterfly; it is repre- 
in Figure 71. It has passed the 
condition, having found shelter in 
it was not directly exposed to the 




sented natural size 
winter in this adult 
some retreat where 
storm and stress of 
the weather. 

When the leaves 
of the elm, willow, 
and poplar trees are 
nearly expanded, 
these butterflies de- 
posit their eggs 
upon the twigs. 
These eggs are laid 
in clusters encirclin 
more in each cluster 




Fig. 71. — The x-Xutiopa Butterfly. 

g the twigs, there being twenty or 
; their general appearance is shown 
71 



Nature Biographies. 



in Figure 72. In the act of oviposition, the butterfly 
keeps her wings spread out, moving the body and abdo- 
men about as the placing of the eggs necessitates. 

About two weeks after the clusters of eoos are thus 
laid upon the twigs of the food-plant, they hatch into 

small blackish caterpillars, each 
emero'ino^ from the eo^or-shell 
through a small hole that it eats 
out of the upper surface. They 
thus enter upon the second stage 
in their life-history — the larva 
or caterpillar stage. As soon as 
hatched, they crawl to the nearest 
leaf upon which they range them- 
selves side by side, with their 
heads toward the margin of the 
leaf. They feed in this position, 
nibbling at the green surface of 
the leaf blade and leaving the net- 
work of veins untouched. 

These caterpillars continue to 
feed in this manner for about a 
week, remainino; side by side when 



r 

\ 

i 


) 


T 






1 


r 


^ 


jTJ^ . - 


'^. 


1 

L 











Fig. 72. — Egg-ring upo 
low Twig. 



Wil- 



feeding, and marching in proces- 
sions from one leaf to another, as 
the food supply is exhausted. Wherever they go, each 
spins a silken thread on the surface traversed, so that the 
combination of all the threads makes a sort of carpet 
that serves as a foothold for the caterpillars. At the 
end of the week they moult or cast their skins, a process 
in which the skin of each larva splits open along the 
back, and the larva crawls out covered with a new skin 
that had been formed beneath the old one. This new 

72 



The Antiopa or Mourning-cloak Butterfly. 



skin stretches somewhat after the caterpillar emerges, so 
that the insect is able to increase considerably in size. 
At the period of moulting, the caterpillars remain quiet 
for a short time, but they soon become active again and 
begin feeding with increased voracity. 

During the next three weeks, this moulting process is 
repeated three times, the caterpillars becoming larger 
each time, and leaving 
their cast skins upon 
the denuded twigs, as 
show^n in Figure 74. 
They soon scatter more 
or less over neighbour- 
ing leaves, but remain 
in closely associated 
colonies (Fig. "jt^). As 
they increase in size, 
they eat more and more 
of the leaf substance ; 
when half grown, they 
devour all but the mid- 
rib and the side veins ; 
but when they get 
larger, only the midribs 
are left. 

The carpet web that 
they form becomes more conspicuous as the caterpillars 
develop, and often binds the ends of neighbouring twigs 
together, especially in those places to which the caterpil- 
lars retire for rest after feedino-. 

About four weeks from the time of hatching, these cat- 
erpillars become full grown (Fig. 76). They then leave 
the tree or shrub on which they have been feeding, and 

7?> 




Fig. 73. 



Colony of Young Caterpillars feed- 
ing upon Willow. 



Nature Biographies. 



scatter about, seeking some sheltered situation. Having 
found this — perhaps beneath a stump or along the 
under side of a fence — each caterpillar spins a web of 
silk along the surface. It then entangles the hooked 

. claws of its hind legs in the 
silken web, and lets- its body 
hang vertically with the 
head end curved upward. 
It remains in this position 
some hours before the skin 
along the back just behind 
the head splits apart and is 
graduall}' wriggled upward, 
until finally it is all removed 
and there hangs in place of 
the caterpillar a peculiar ob- 
ject having no definite form. 
But it rapidly assumes a 
definite form — that of the 
chrysalis (Fig. 77). This 
picture shows the shape and 
size of the chrysalis, which 
is of a orravish brown colour, 
different specimens varying 
somewhat in shade. 

In this quiet chrysalis, the 
insect is apparently almost 
as inert as a mummy. If you touch it, it will wriggle a 
little, but otherwise it hangs there mute and helpless. 
On the inside, however, the tissues are being made over 
in such a wonderful way that in about two weeks, from 
the mummy case into which the caterpillar entered, there 
comes a beautiful butterflv. 

74 




Fig. 74. 



■Cast Skins upon a Denuded 
Twie. 



The Antiopa or Mourning-cloak Butterfly. 



When this butterfly first breaks through the mummy 
shell, its v/ings are very small, although its body, antennae, 
and legs are well 
developed. By 
means of the lat- 
ter, it clings to the 
empty chrysalis, 
while its wings ex- 
pand. At first 
these wings are 
short, but as soon 
as the insect takes 
a position in 
which the wings 
hang downward, 
they begin to ex- 
pand, and soon 
reach full length, but are more or less crumpled longitu- 
dinally, and the front wings are not so wide as the hind 

ones, hanging limply inside 




Fig. 75. 



Half-grown Caterpillars feeding on Elm 
Leaves. 



i^'-^ 




Fig. 76. — Full-grown Caterpillars. 



the latter, as shown in Fig- 
ure 'jd>. In a short time, 
however, they expand later- 
ally and become full size, 
the butterfly still hanging 
to the chrysalis, as shown 
in Figure 79. 

After the butterfly has 
thus reached its full form 
and size, it crawls from the 
chrysalis to some neigh- 
bouring support, where it 
rests quietly for half an 



75 



Nature Biographies. 




Fig. 77. — Chrysalis. 



hour or more. During the latter part of this time it ex- 
ercises its unused muscles by slowly opening and closing 
its wings, until finally it flies away. 

The cateipillars of the mourning- 
cloak butterflies are restricted to 
comparatively few food-plants. In 
regions where they are not especially 
abundant, they are likely to be found 
upon willow, poplar, or elm. In 
general, as many observations indi- 
cate, they are as likely to be found 
upon any one of these food-plants 
as upon either of the other two ; 
but in certain localities where they 

become especially abundant it seems that they are more 
likely to occur upon the elm. On this account they have 
been called the Spiny Elm Caterpillars. There is con- 
siderable evidence to show that 
they prefer the American elm to 
other species of the genus, although 
in the case of willow and poplar 
there seems to be little if any pref- 
erence as to the species. 

Miss Caroline G. Soule has seen 
the butterflies depositing their eggs 
upon the white and canoe birch, 
and it has been recorded as feeding 
in Labrador and Europe upon a 
species of birch. There is one 
record of the caterpillars having 
been found feeding upon the hack- 
berry, and also one of their hav- 
ing fed greedily upon the leaves 
76 




Fig. 78. — Butterfly with 
Wings developing. 



The Antiopa or Mourning-cloak Butterfly. 



of rose, and still another of their having almost de- 
foliated a pear tree. Linden and nettle are also in- 
cluded in the European lists of the food-plants of this 
species. 

It is evident, however, that all of these, except the 
three first named, — willow, poplar, and elm, — are to be 
regarded as exceptional cases, and that the normal food 
of the species is the foliage of 
a plant belonging to one of 
these three genera. 

It has generally been sup- 
posed that this species is 
double-brooded in central and 
southern New England, the 
butterflies of the first brood 
appearing early in July. These 
are said to deposit eggs which 
hatch into caterpillars that 
mature into butterflies early in 
September. These butterflies 
live through the winter, laying 
eggs the following spring. 

Unless the summer of 1899 was exceptional, however, 
this idea of the yearly history of the species will hc:ve to 
be modified, for during this season, in New Hampshire 
and Vermont at least, there was practically but one 
brood. Continual observations by Miss Caroline G. 
Soule at Brandon, Vermont, and by Mr. W. F. Fiske and 
myself in this state show that there was scarcely a trace of 
a second brood of caterpillars, for with all our searching 
in July and August we found but a single colony of 
larvae. These were discovered on a willow at Durham, 
August 3. During the period when the second brood 

77 









1 






■ 


HUH 





Fig. 79. — Butterfly hanging to 
Empty Chrysalis. 



Nature Biographies. 

of caterpillars are supposed to be at work, I travelled by 
carriage and on foot over hundreds of miles of roadway 
in southern New Hampshire and southern Maine, and 
though there was everywhere evidence of the presence 
of the first brood, none of the second were seen. During 
the same period Miss Soule was watching in northern 
Vermont, and Mr. Fiske took an extended trip through 

central New Hamp- 
shire. But save for 
the single colony 
mentioned, all our 
looking did not re- 
veal a trace of the 
second brood. Nor 
was there a single 
complaint from cor- 
respondents of in- 
jury at the supposed 
time of the second 
brood, although 
many accounts of 
the depredations of 
the first brood were 
: y_ received. 

Fig. 8o.-The Spiny Elm Caterpillars. I^^ vicw of all this 

evidence, it seems 
safe to conclude that in northern and central New Eng- 
land, at least, a single brood is the rule rather than the 
exception. This involves the conclusion that the butter- 
flies seen upon the wing early in autumn are the same 
ones that developed in July, and that these same but- 
terflies remain alive through the winter and until, in the 
following May, they lay their eggs. Thus there is a 

78 




The Antiopa or Mourning-cloak Butterfly. 

period of ten months of existence in the butterfly state, 
an extraordinary length of time for a butterfly to Hve. 

To a large extent the butterflies disappear in August, 
and the question arises as to what becomes of them. 
Our observations lead to the conclusion that they go 
into summer quarters similar to those which they seek 
out for winter shelter. Apparently they fly about for a 
few^ days after coming from the chrysalis and then retire 
to cool woods, where under the side of a log or beneath 
the loose bark of a dead tree they settle down and to all 
appearances go to sleep. The in- ,^ 
stinct to remain quiet is very strong 
in these butterflies. In taking the 
accompanying photographs, I found 
that even shortly after coming from 
the chrysalis the butterflies when 
disturbed would fold their wings 
with the antenna between them, 
and drawing the legs against the - ^ 
body would lie quietly on their sides ^^^- s^-- Butterfly in Rest- 

•^ ... ing Position. 

for a long time; the position thus 
assumed by the living butterfly is shown on page 71. 
These same butterflies would also hang downward from 
a limb by the hour in the hibernating position as shown 
in Figure 82. 

In the cooler weather of early autumn, the butterflies 
come from their retreats and fly about in the sunshine. 
They are especially likely to be seen along the borders of 
woods or in open glades. At this time they love the 
sunshine, and will settle in a sunny place to bask in it. 

On a springlike day early in November (the 8th) I 
came across one of these butterflies basking in the sun- 
shine upon the ties of a railway track. It rested with its 

79 




Nature Biographies. 

Avings wide open. On being disturbed, it would fly a 
short distance and then alight, and I was interested to 
notice that after ahghting it would always turn about 
until the hind end of its body pointed in the direction of 
the sun, so that the sun's rays struck its wings and body 
nearly at right angles. I repeatedly observed this habit 
of getting into the position in which the most benefit 
from the sunshine was received, and it is of interest as 



/ 




Fig. 82. — Butterfly in Hibernating Position. 



showing the extreme delicacy of perception toward the 
warmth of sunshine which these creatures possess. 

During the colder part of the year in bright weather 
wdien these butterflies are most often abroad, they com- 
monly hold their wings open when they alight, but dur- 
ing the warmer summer days, they are more likely to rest 
with the wings closed. 

When the warm days no longer tempt them abroad, 
the mourning-cloak butterflies seek shelter in many 
sorts of situations, — under loose bark, in hollow trees, 
under cuh^erts and bridges, in woodpiles, in crevices of 

80 



The Antiopa or Mourning-cloak Butterfly. 

rocks, or alongside logs lying on the ground. In such 
retreats they remain until the sunshine of spring again 
calls them forth. 

The mourning-cloak butterflies subsist upon a con- 
siderable variety of liquid food which they suck through 
their long tongues. In spring, when they first come from 
their winter quarters, they visit the stumps of recently 
cut trees and suck the exuding sap, a habit which they 
continue whenever opportunity offers. Mr. Fiske has 
noticed that they commonly sip the sap of maple twigs 
where the squirrels have gnawed the bark. A little later 
they visit the willow catkins to suck the nectar secreted 
by these blossoms, and still later they hover about the 
delicate blossoms of the mayflower, or trailing arbutus, 
for a similar purpose. Probably many other flowers are 
thus rifled of their sweets, although this butterfly seems 
to be a less regular visitor to flowers than are many of its 
allies. A little later, when the aphides, or plant-lice, have 
become sufficiently abundant so that the so-called "honey 
dew" is to be found upon the infested shrubs, these 
mourning-cloaks sometimes sip the liquid sweet from 
the surface of the leaves. In April and May they occa- 
sionally visit the flowers of moosewood, and later in the 
season have been observed upon the blossoms of the 
common milkweed. From tl^iC time the early apples 
ripen these butterflies may often be seen beneath the 
orchard trees, sipping the liquids of the fallen and 
decaying fruit. 

In Germany this butterfly is called Trauerinantel, from 
the translation of which is derived the common American 
name, mourning-cloak. Its other common name with 
us, Antiopa butterfly, is derived from its Latin name, 
Vanessa antiopa. In England it is called the Camber- 

8i 



Nature Biographies. 

well Beaut}^ from its having been found at an early date 
at or near Camberwell. A still earlier title adopted for 
it in England was '' The Grand Surprise," given by 
butterflv collectors because at the beo'inninor of the cen- 
tury, after a long absence, it appeared in considerable 
numbers. 

In most books upon insects the technical name of this 
butterfly is given as Vanessa antiopa. In his recent 
writings Mr. S. H. Scudder has called it Eiivanessa 
antiopa, although in one of his earlier books he called it 
Papilio antiopa. Questions of nomenclature, however, 
need no consideration in this connection, and I mention 
these names only for the guidance of any reader that may 
wish to study what has been printed about the species. 

During the earlier years of our country's history many 
people regarded these caterpillars as '' venomous and 
capable of inflicting dangerous wounds." Dr. T. W. 
Harris states that he had known people to cut down pop- 
lar trees around dwellings to prevent the presence of 
such dangerous caterpillars. But these insects are not 
poisonous, and may be handled with little fear of injury, 
although the sharp spines might perhaps penetrate the 
delicate skin of a child's hand. 

The mourning-cloak butterfly is one of the most 
widely distributed insects in existence. Not only is it 
found in North America as far south as Bermuda, Flor- 
ida, and Mexico, but it is also found throughout north- 
ern Europe, and in Asia and Japan. Consequently, as 
Mr. Scudder has said, it appears to be distributed " over 
the entire breadth of the northern hemisphere, below 
the Arctic circle as far south as the thirtieth parallel of 
latitude." This is an extraordinary distribution for an 
insect, and shows a remarkable power of adaptation to 

82 



The Antiopa or Mourning-cloak Butterfly. 

the varying surroundings in which the species occurs. In 
the northern United States this is one of the common- 
est and most famihar butterflies. 

As a rule, the caterpillars of the mourning-cloak 
butterflies are to be found only in occasional colonies, 
so that the damage they do attracts little if any atten- 
tion. But sometimes the weather or other conditions 
are so favourable to their development that they multiply 
beyond this normal limit and are to be found in great 
numbers. At such times serious damage is often done. 
In this country such local outbreaks of the species have 
frequently occurred, generally, however, over very limited 
areas. So far as I can learn, the insect has never caused 
such widespread destruction as the forest tent caterpillar 
has recently caused in New England. In the tree planta- 
tions of the prairie regions of the West, these cater- 
pillars are, according to Professor Otto Lugger, " very 
injurious, and sometimes denude whole rows of wdllows 
and poplars." The same observer adds, " They are 
still more fond of the leaves of elms, and I have seen 
them so numerous upon those trees in Michigan that 
branches were broken by their weight." In other 
regions of the West similar records have been made. 

Like most other insects, the mourning-cloak butter- 
flies have many natural enemies to contend against. 
From the moment the egg is laid until the butterfly dies, 
it is in constant danger. 

Some of the eggs never hatch into caterpillars because 
a tiny fly, scarcely one-twentieth of an inch in length, 
finds the egg mass, and deposits in each egg another 
egg, the latter being microscopic in size. This tiny 
egg soon hatches into a maggot almost equally tiny, 
and the maggot grows by absorbing the contents of the 

83 



Nature Biographies. 



butterfly egg. In due time it changes to a minute pupa, 
later to a minute fly, Uke the one that laid the micro- 
scopic egg. This minute fly now gnaws a hole through 

the egg-shell of 
the butterfly and 
comes out into the 
world. The little 
creature that has 
thus developed at 
the expense of the 
egg of the butter- 
fly is called an egg 
parasite. There 
are many species 
of these egg para- 
sites, and they at- 
tack the eggs of 
many kinds of 
insects. The par- 
ticular species that 
develops in the 
eo^o^s of the mourn- 
ing-cloak butterfly 
is called by scien- 
tists Telejionius 
graptce. An dc- 
count of the way 
in which these little flies oviposit in the Antiopa eggs 
will be found farther on in this book. 

After hatching from the egg, the caterpillars are sub- 
ject to the attacks of various parasites. One of these is 
quite minute, not a great deal larger than the egg 
parasite. It is a tiny four-winged fly which deposits 




Fjg. ^i. — Poplar Twig defoliated by Antiopa 
Caterpillars. 



The Antiopa or Mourning-cloak Butterfly. 

many eggs in a single caterpillar. The eggs hatch into 
tiny maggots that grow at the expense of the caterpillar, 
finally killing it and changing to four-winged fiies again. 
As many as 145 of these parasites have been known to 
emerge from a single dead caterpillar. These little flies 
are called CJialcids by entomologists. 

There is still another group of four-winged flies, some 
of which attack the Antiopa caterpillars. These are 
much larger than the Chalcid flies and are called Ich- 
neumon-flies. In the case of these, only one or two para- 
sites develop in each caterpillar or chrysalis. 

In addition to these various four-winged flies, there 
are certain two-winged flies, called Tachmid Flies, that 
develop at the expense of the caterpillars. In New 
Hampshire, during recent years, these appear to have 
been the most abundant parasites of these insects. An 
^^^ is laid on the skin of the caterpillar by a two-winged 
fly, similar in general appearance to Figure 85. The 
contents of this ^^^ shortly develop into a tiny grub 
that burrows through the egg-shell and the skin of the 
caterpillar into the inside of the body. Here it remains 
absorbing the body substance of its host and gradually 
increasing in size. In a few weeks it becomes fully 
developed in this grub state. By this time the caterpillar 
has become sluggish from the effects of the parasite. 
If the branch upon which it feeds is disturbed, the other 
caterpillars are likely to crawl away, but it remains in 
its place. The caterpillars illustrated on the web in 
Figure 84 were parasitized specimens that thus re- 
mained after the others had crawled away. 

Shortly after becoming full grown, the Tachinid grub 
breaks through the skin of the dying caterpillar and, fall- 
ing to the ground, changes to a peculiar pupa ; the outer 

85 



Nature Biographies. 




undero^oes 
change 



skin of the grub turns brown and becomes hard, form- 
ing a protective covering for the body inside. A week 

or two later the insect 
another 
and emerges 
as a two-winged Ta- 
chinid fly, hke the one 
that laid the egg some 
weeks before. 

Besides those insects 
that develop on the 
inside of the bodies of 
these Antiopa cater- 
pillars, called parasites, 
there are other insect 
enemies which attack 
them from the outside 
and devour them bodi- 
ly. The most notable 
of these, perhaps, is a 
large beetle commonly 
called the Caterpillar 
Hunter; it is known 
to entomologists as Calosoma scrutator. This is a very 
active insect, with large strong jaws, 
that runs rapidly about in search of 
victims. In some cases it has been 
observed while destroying many of the 
Antiopa larvae. 

In the Southern states a common 
reddish wasp — a species of Polistes — 
has been also observed attacking these caterpillars, and 
there are probably various other insects that destroy 



Fig. 84. — Parasitized Caterpillars remaining on 
Twig after Healthy Ones have left. 




85. — Tachinid 
Parasite. (Slightly 
magnified.) 



The Antiopa or Mourning-cloak Butterfly. 



them, although definite observations showing this have 
not been recorded. 

The Antiopa caterpillars are such spiny creatures that 
comparatively few birds attack them. They are devoured, 
however, by the two species of cuckoos, — the yellow- 
billed and the black-billed, — and it is probable that they 
are sometimes killed by Baltimore orioles and various 
other birds. They are also greedily devoured by toads, 
but of course they do not often come within the reach of 
these useful ani- 
mals. \ 

Even the adult 
butterflies of this 
species have to be 
on the lookout for 



enemies. 



During 




Fig. 86. — Butterfly attacked by Maryland 
Yellowthroat. 



the long months of 
their life many of 
them probably suc- 
cumb to the attacks 
of birds or other 

creatures. I have seen but one such tragedy. While 
riding along a country highway with a bird-loving friend 
one spring day w^e saw a male Maryland yellow-throat 
flit by with a mourning-cloak in his mouth. The bird 
lit on a fence, from w^iich I startled him so that he 
dropped the butterfly, a worn and faded, half-dead speci- 
men that I photographed, and show in Figure 86. The 
places where the bird held the insect are probably indi- 
cated by the m.issing pieces of the wing. 

In general, the most satisfactory remedy for these cat- 
erpillars is to cut off while they are still young the 
branch on which they are feeding, and crush or burn the 

87 



Nature Biographies. 



Insects. After they become larger they may be shaken 
off and crushed. Or the colonies may be brought down 
with a torch, care being taken to kill the caterpillars that 
fall to the ground, as probably many of them will not be 
seriously injured by the flame. Jarring the limbs with a 
padded mallet will also be a useful way of bringing dow^n 
those out of reach ; or they may be brought down by 
use of a strong stream of water from a force pump or 
hydrant. They are also open to destruction through 
^ spraying with arsenate of lead or other 

forms of arsenical poisons. 

An interesting exhibition of popular 
ignorance occurred during a recent 
outbreak of these caterpillars when 
many owners of shade trees in a New 
England city applied bands of various 
sorts to the trunks of the trees to pre- 
vent the injury. Presumably this was 
done on the theory that as bands are 
successfully employed against canker- 
worms, they are equally good against 
other caterpillars. In the case of canker-worms, how- 
ever, the female moth w^hich lays the eggs is wingless, 
so that the bands prevent her from ascending the trees. 
But with the spin)^ elm caterpillar the parent insect 
that lays the eggs is a butterfly which can easily fly to 
the tops of the tallest trees. The eggs are deposited on 
the twigs by these butterflies, and the caterpillars remain 
in the close neighbourhood of the place where they hatch 
until they are full grown. Consequently, any banding 
of the tree is a waste of energy so far as this insect is 
concerned. 




Empty 



Chrysalis. 




LOCUST MUMMIES. 

^ Last autumn one could easily find a 
great many dead locusts attached to 
fences, the bark of trees, the sides of 
buildings, and in other elevated situa- 
tions. Although dead they appeared 
to be alive, and it was only by touch- 
ing them that one discovered that 
they were not only dead but so dry 
and brittle that they easily broke 
apart. Sometimes I found one just 
alive, so that when touched it would 
move a leg or an antenna, but was unable to jump away. 
These grasshoppers were nearly all of one species — 
the large Carolina Locust^ which was unusually abun- 
dant last summer. This insect is especially common 
along roadsides and in open grasslands near houses. It 
is the one most generally " flushed " as you walk along 
the country highway ; at such times it flies rapidly in 
a more or less irregular, zigzag fashion, and generally 
alights a rod or two in front of you. When flying, its 
black, under wings, with their cream-coloured borders, are 
very conspicuous ; but the moment it alights, these dis- 
appear, being covered by the dusty-brown wing covers, 
which so blend with the soil that the insect is difficult to 
observe until it flies again. 

The dead grasshoppers clinging to the trunks of trees 
and other things were generally dry and brittle. By 

^ Dissosteira Carolina. 



Nature Biographies. 

breaking them apart one could see that the body was 
more or less filled with a w^hitish substance which appar- 
ently had absorbed all the living tissues. It was because 
of the mummifying effect of this white material that the 
insects clung to their support so tenaciously long after 
they were dead. 

These grasshoppers were the victims of a parasitic 
plant that had invaded their tissues and destroyed theii- 
lives. This plant is a fungus w^hich reproduces by means 
of minute spores, so light as to float in the air, and so 
small as singly to be invisible to our unaided eyes. 
When one of these chances to fall upon a grasshopper, 
especially if moisture be present, it is likely to germinate 
by sending out a little tube. Should the spore be beside 
one of the spiracles or breathing pores of the insect, it 
would probably enter the body through this tiny opening. 
When it gets inside it continues to grow rather rapidly, 
absorbing the tissues and penetrating most parts of the 
body. The result is that the grasshopper is soon killed 
and its body mummified. 

It is a curious fact that locusts affected by this strange 
disease are impelled to climb as high up in the w^orld as 
they can get. Sometimes they will reach a position eight 
or ten feet from the ground. They very commonly crawl 
up the stalks of grasses and various herbaceous plants, 
especially goldenrod, as may be seen in the pictures 
herewith. Once one w^as brouo^ht me clino-ino: to the 
fair white petals of a beautiful Blanche Burpee sw^eet 
pea ; it was so striking a situation that I made the 
photograph w-hich is reproduced in Figure 88. 

The bodies of these mummified locusts are generally 
broken up by wind and rain before winter sets in. Late 
in autumn you will find them still clinging to their various 

90 



Locust Mummies. 

supports, but with many of them parts of the body are 
gone. The first storm of sleet and ice, however, gener- 
ally breaks off such specimens, so that in winter you can 
seldom find any of the mummies in the places that knew 
them before. 

Under favouring conditions of warmth and moisture, 
the fungus in these dead locusts w^ill develop a crop of 




Fig. 



— Dead Locust clinging to Sweet Pea. 



spores that will cover the insects with what looks like a 
fine white mould. It is by means of these .that the disease 
is propagated. 

These parasitic plants play an important part in the 
great drama that is sometimes called the Balance of 
N^atitre. Every species of animal tends to multiply to 

91 



Nature Biographies. 



an extent that would crowd the others out of existence. 
To counteract this tendency there are a host of agencies. 
In the world of insects, for example, species is set over 
against species in such a way that under natural con- 
ditions it seldom happens that one kind becomes over- 
whelmingly abundant. And when this happens Nature 

calls to her aid these parasitic 
plants which commonly make 
short work of the offending in- 
dividuals. 

Aside from the Bacteria, the 
most important plant parasites of 
insects belong to a group called 
EntoiiiophtJwrccs by the botan- 
ists. Most of them belong to 
the genus Empusa. In their 
structure these plants are allied 
to the moulds, but nearly all of 
them have the striking peculi- 
arity that they can develop only 
upon certain forms of living in- 
sects. Every one has seen the 
Empusa tliat attacks the com- 
mon house-fly; it is this plant 
that causes the dead fly to adhere 
to the walls and window panes ; 
the halo of white powder that commonly surrounds 
the insect consists of the reproductive spores of the 
fungus. 

A strikino- illustration of man's indebtedness to these 
Empusas in keeping in check outbreaks of injurious 
insects has lately been seen in Maryland, Delaware, and 
other North Atlantic states. In many regions in this 

92 




Fic. 89. — Dead Locust cling 
ing to Goldenrod. 



Locust Mummies. 



territory the growing of peas for canning is an important 
industry. Until lately there has been very little difficulty 
in raising the crop, few insects having become trouble- 
some to the plant. In 1899, however, a plant-louse, or 
aphis, appeared suddenly on the vines over a large area, 
and soon destroyed much of the 
crop. In 1900 the attack was re- 
peated with results that were almost 
equally disastrous. 

Even the entomologists at first 
were puzzled to determine where 
such enormous numbers of the plant- 
lice came from so suddenly. For 
some time it was supposed to be an 
undescribed species ; it belonged to 
the genus Nectarophora, and the 
specific name destructor was pro- 
posed for it. It was later found, 
however, to be a species long known 
in Europe as Nectarophora pisi, and 
the careful studies of several official 
entomologists soon showed that the 
pests came to the peas from the sur- 
rounding clover fields, where they 
had probably been breeduig unno- 
ticed for many years. 

In 1900 these aphides were sud- 
denly checked during June by an 

outbreak of a fungous disease caused by Empiisa aphidis. 
After its appearance in the infested fields this fungus 
spread from host to host very rapidly, and finally killed 
almost all of the plant lice. This fact led to the sugges- 
tion that probably this disease usually keeps the pests in 

93 




Fig. 90. — Dead Locust 
clinging to Grass. 



Nature Biographies. 

check, and that the reason there had been so serious an 
outbreak was because the weather conditions had been 
unfavourable to the spread of the disease, and conse- 
quently favourable to the unlimited multiplication of 
the insects. Professor E. D wight Sanderson, of the Del- 
aware State College, has stated the conditions observed 
in the following paragraph : — 

" The chief natural factor in the control of the pest 
seems to be the fungous disease Eviptisa aphidis. The 
growth of this fungus requires slightly warm, wet 
weather, and is prevented by drought. April, May, and 
June of 1899, in Delaware, Maryland, and New Jersey, 
were altogether the driest for the past ten years, and 
with local exceptions this was true throughout the At- 
lantic Coast, Ohio Vallev, and Lake Resfion. Followino- 
this, April and May of 1900 were almost equally dry, 
though in June the rainfall was much above the normal. 
In 1899 the fungus did not destroy any considerable 
number of the Hce until about June 18, and from all 
accounts their destruction was most largely due to pre- 
daceous insects. In 1900 the disease appeared much 
earlier, destroyed large numbers of the lice, and their 
disappearance by the i8th of June was mostly due to it. 
In 1890 the lice were destroyed by this disease at 
Newark, Del., on clover by May 12. The rainfall of 
May, 1890, was above the normal at Newark, and the 
preceding winter was an unusually mild one, seemingly 
corroborating the view^ that a wet spring is favourable 
to the development of the fungus, which destroys the 
aphids on the clover and prevents them from becoming 
numerous enough to spread to peas." 

It is the frequent recurrence of such experiences as 
this that convinces the entomologist that he ought to 

94 



wmmmmmmm^mm 



Locust Mummies. 

have the fullest possible knowledge of the life-history 
and enemies of every species of insect, whether it may 
have at present any apparent economic importance or 
not. And so he is always making observations on as 
many of the insects of his region as he is able, knowing 
that all such knowledge has real value, and may at any 
time become of great practical importance. 



95 



CATCHING BUTTERFLIES WITH A CAMERA. 




To paraphrase a famous saying in re- 
gard to hare stew : If you would 
catch butterflies with a camera, you 
should first get your caterpillars. 
For though caterpillars are not but- 
terflies, they are butterflies in the 
making, and they will show you most 
interesting stages in Nature's manu- 
facture of these dainty and exquisite 
creatures. This, however, is not my 
chief reason for giving the advice. 
You doubtless desire to make perfect pictures; and a 
perfect picture of a butterfly should show colour values 
and the details of structure — a result that is not to 
be obtained by the 
process of pressing 
the button. It is 
rather to be secured 
by a long exposure 
through a c o 1 o u i" 
screen and a small dia- 
phragm opening in a 
room where the light 
is not too briorht. 

To make a picture 
under these conditions you must have a docile subject, 
and the butterfly afield is not a docile subject. You are 
fortunate if out of doors you get a snap-shot in focus, 

^96 




Fig. 91. — The Painted Beauty Butterfly. 



Catching Butterflies with a Camera. 



and when you bring these day-fliers indoors, they will be 
attracted to the window as certainly as their cousins, the 
night-fliers, are attracted by a Hght. Under such con- 
ditions sweets and flowers are unavailing to hold their 
attention ; the sunshine in the window is always calling. 
But fortunately for the photographer, there is one brief 
period in a butterfly's life when it is so docile that it will 
pose for five minutes at a 
time. This is the period 
soon after it emerges 
from the chrysalis, when 
its wings are fully devel- 
oped, but before they 
have hardened and be- 
come strong enough for 
flight. At this time the 
butterfly is perfect — 
every scale in its place, 
every spot of colour at 
its best; like a bride 
arrayed for the wedding, 
the beautiful creature is 
in the first flush of its 

Fig. 92. — Caterpillar feeding on Everlasting. 

perfection. And it will 

rest quietly upon a flower, a leaf, or a twig while you 

adjust the camera and expose the plate. 

Many people think that for indoor photography a studio 
with light from above is necessary. But for still life — 
such as flowers and butterflies — lio-ht from a side win- 
dow can be used to equal, if not greater, advantage. In 
such pictures you want roundness and detail rather than 
flatness and lack of detail. The side light will give 
roundness, the degree of shadow being easily regulated 

97 




Nature Biographies. 

by white cardboard reflectors, and the long exposure 
will give the detail. In a room lighted by only side win- 
dows the accompanying pictures were taken, through a 
bichromate of potash colour screen and the smallest of 
diaphragm openings. The exposure varied from three 
to five minutes, the plates being orthochromatic and 
slow, or medium in sensitiveness. 




Fig. 93. — Caterpillar Ready to Puj)atc. 



hn;. 94. — 1 he Chrysalis. 



The laro;er butterflies are amono^ the most interestinor 
subjects for the would-be photographer of insects. It is 
a comparatively easy matter to get a set of pictures rep- 
resenting the life-stages of one of these creatures, if you 
are willing to devote to it the necessary time and atten- 
tion. Suppose you wish to illustrate the life-history of 
the beautiful hunter's butterfly, which is also called the 
Painted Bcmity. The caterpillars of this insect may be 

98 



mammm 



Catching 



Butterflies with a Camera. 



found on the leaves and among the blossom heads of the 
common tall everlasting, a plant of the genus Gnapha- 
lium. These caterpillars have the peculiar habit of mak- 
ing protective cases by gnawing off the woolly hairs 
of the food-plant and 

binding them together .^ 

by silken threads. 
Within or beneath 
these cases the larvae re- 
main, feeding upon the 
substance of the leaves. 

As the caterpillars 
approach maturity, 
they generally web 
together the upper 
leaves and the flower 
heads to make a sort of 
airy cell, in the middle 
of which they remain 
until full grown. 
Many of them at this 
time seem to care less 
for concealment than 
they did earlier, as 
their cottony coverings 
are more open. 

When the caterpillar finally becomes full fed, it spins 

a mass of silk against the upper part of its cell, in which 

it entano^les its hind le^s and lets itself hans: downward 

as shown in Figure 93. In a short time it wriggles off its 

caterpillar skin and hangs in the cell as a pupa (Fig. 94), 

where it remains unchanged for about a fortnight. Then 

the pupa skin splits open, the butterfly drops out, and 

99 
LofC. 




Fig. 95. — Newly Emerged Butterfly, 



Nature Biographies. 



catches hold of the mass of leaves and blossoms with its 
legs, its body and the undeveloped wings hanging down- 
ward. In the course of the next half hour the wings 
expand until they are full size, the front pair being en- 
closed by the hind pair, 
as may be seen in Fig- 
ure 95. Before long 
the unused muscles 
acquire more strength 
and the newly fledged 
butterfly walks to the 
I .MRPfe^'",*^ top of the flowers, 

where it rests quietly 
for half an hour or so. 
It is now very docile 
and in an excellent 
mood for o-ratifvino- the 
whims of the photog- 
rapher. Though it can- 
not always be depended 
upon to remain two or 
three minutes in a given 
position for you to get 
an exposure through 
the colour screen, it will 
do so often enough for 
a high average of good 
pictures. But it will not hold its wings open for you, 
coax it as you may. 

After about an hour of such rest the butterfly is likely 
to begin moving its wings, slowly opening and closing 
them to get the untried muscles ready for flight Then 
the light of the window will prove too attractive for 

100 




Fig. 96. — Preparing to ll\ 



Catching Butterflies with a Camera. 



longer quietude. After this you may succeed in getting 
a few good pictures, but 
the best mood of your 
model has passed. | 

There are many other ' 
butterflies that will lend 
themselves in a similar 
way to the uses of the pho- 
tographer. The common 
mourning-cloak or Anti- 
opa butterfly is a particu- 
larly docile subject, as is 
also the beautiful monarch 
butterfly. With those 
species that hibernate as 
adults, some attitudes will 
be held for a long time, 
even after the butterflies 
have moved about for a 
while. This appears to 

be an instinctive trait, due probably to the fact that in 
hibernation they remain quiet for months. 




Fig. 97. — Visiting an Aster. 




Fig. 98. — Tlie Mourning-cloak I'utterfly, 
lOI 



AN INSECT POTTER. 




In the vast number of insects that Hve 
in the world a great variation is to be 
found in the manner of existence. As 
one studies these creatures he is led 
more and more to wonder at the mar- 
vellous contrivances and adaptations 
by means of which many of them are 
enabled to live. Even in a sinole 
group, such as that of the wasps, there 
is great diversity of habit : many wasps 
live in colonies in paper nests with which most people 
are familiar; others dig holes in the ground and live 
there; others take advantage of hollow stems in shrubs 
and herbaceous plants, and a few even build miniature 
houses on the outside of the stems of plants. 

Amono- the insects that have the habit last mentioned 

o 

perhaps none is of greater interest than the Fraternal 
Potter Wasp, called by the entomologists Enmenes 
fraterna. This is a pretty little thread-waisted insect, 
black except for creamy yellow markings on the body 
in the places shown in accompanying pictures. When 
straightened out, it is about three-fourths of an inch 
long. 

These wasps are of special interest because they build 
the little earthen houses shown also in the picture. 
Selecting some small stem, preferably one having thorns 
upon it, the mother wasp brings tiny loads of sandy soil 

102 



■■■■ 



An Insect Potter. 



which she cements together with her saHva, gradually 
building up a hollow earthen cell, nearly round, and 
about half an inch in diameter. Often the shape when 
completed is suggestive of a flattened jug, without a 
handle, but with a slight projection where the mouth of 
the iuo- would be ; this is well 
shown in the lower cell in one 
of the pictures (Fig. loo). 

For what purpose does the lit- 
tle potter toil so diligently ? For 
the same purpose that makes the 
lives of so many adult insects a 
round of ceaseless activity — that 
of providing for the young. 
When the cell is nearly finished, 
the wasp searches the leaves of 
trees and other plants for small 
caterpillars which after being par- 
alyzed by stinging are brought 
to the little house upon the 
thorny twig. When enough of 
these are found, an egg is laid in 
the cell which is then sealed up. 

In the case of some species 
the egg is hung from the top of 
the cell on the end of a tiny 
silken thread. When it hatches, the larva holds on to 
the empty egg-shell and reaches out to feed upon the 
caterpillars stored so abundantly just below. 

The larva that thus feeds upon the caterpillars, placed 
in the cell by the provident mother, lives in darkness 
and alone except for the paralyzed caterpillars that await 
its devouring jaw^s. In due time it becomes full grown 

103 




Fig, 99. — Two Eumenes and 
the Cells from which they de- 
veloped. 



Nature Biographies. 




in this larval stage, having eaten all the victims immured 
within its earthen house ; then it changes to a quiet pupa, 
which shortly afterward transforms to an adult wasp that 

gnaws a hole through the 
side of the house and comes 
forth to build more houses, 
and provide for the next gen- 
eration. 

Most of the wasps that build 
earthen cells for the develop- 
ment of their young place 
them in such shelter that they 
are protected from the rain. 
But this Eumenes, like the 
other species of the genus, 
builds habitually in exposed 
situations, commonly on plant 
stems, sometimes on rocks. 
Yet these houses of mud are 
unaffected by the rain that one 
would think might cause them 
to crumble. If you look at the 
cell through a lens, you see 
that it is composed of a great number of tiny pebbles, 
mostly quartz, cemented solidly together. 

We owe much of our knowledge of the habits of 
Eumenes to the French entomologist, J. H. Fabre, whose 
Souvenirs Entomologiqiies have well been called " the 
most interesting and delightful of all entomological 
papers." ^ It was he who showed that the mother wasp 
obtains her cement for the w^alls of her house by selecting 



Fig. ioo. — Eumenes and Cells. 



1 George W. and Elizabeth G. Peckham. 
Solitary Wasps. Preface. 

104 



Instincts and Habits of the 



■■■ 



An Insect Potter. 

particles of very dry dust and mixing it with her saliva. 
She thus forms a mortar that hardens quickly and holds 
firmly, despite the bluster of rain and wind. 

Fabre's account of his discovery of the hanging tgg 
and its subsequent larva is of such interest that I quote 
it in a free translation. Before he discovered how^ the 
Eumenes larva fed, he had made many unsuccessful 
attempts to rear it. He finally concluded that there 
must be some way in which the insect was kept out of 
the reach of the writhing mass of its victims. 

" I had an ardent desire," writes Fabre, " to learn of 
the stratagem employed by the larva. I would not be re- 
buffed by the rarity of the nests, the pain of investiga- 
tion, the heat of the sun, or the vain fracture of empty 
cells : I would see and I have seen. And mv method 
was this : I made, with knife and forceps, a side window 
in the dome of the cell. Great care is necessary in order 
not to injure the occupant. When the opening is large 
enough to see the interior, I stop. And I found this 
condition : the ^<gg is not deposited on the food ; it is 
suspended from the dome by a thread, as fine as that of 
a spider's web. The delicate cylindrical ^gg vibrates at 
the least breath. It reminds me of the famous pendu- 
lum suspended from the dome of the Pantheon to dem= 
onstrate the earth's rotation. In a heap below is the 
living food. 

" By opening a window in another cell we can see the 
second act in this marvellous drama. The larva we find 
is already growing. Like the ^%%, it hangs suspended, 
attached to the thread by the hind part of its body. But 
the thread is longer ; in addition to the slender filament 
that held the ^gg there is a sort of ribbon. The larva 
is feeding ; with lowered head it is devouring one of the 

105 



Nature Biographies. 

caterpillars. I touch another of the waiting victims with 
a spear of grass. It moves, as do its neighbours, and 
the Eumenes larva instantly withdraws from the melee. 
But how ? To my surprise I find that what I took for a 
bit of flat ribbon attached to the thread, is a sheath, a 
scabbard, into which the larva retreats. And this is 
simply the empty egg-shell, transformed into a refuge 
for the larva when the writhing caterpillars below be- 
come dangerous." 

When the larva becomes larger, it leaves the suspended 
shelter and feeds at will among the paralyzed caterpillars. 
And thus it is able to complete its growth and become 
a mature wasp to continue the propagation of the species 
by means of the strange set of instincts that have been 
developed through long ages of existence. 



1 06 



■H 



wmmm^i^mmmmmmm 



THE CAMERA AND THE ENTOMOLOGIST. 



The camera is like the human eye : 
it sees whatever its owner is inter- 
ested in. If he love beautiful 
landscapes, it gives him pictures 
of them; if he love the fleecy 
clouds, it brings them down to 
him ; if he love children and happy 
human faces, it gives them to him 
for his lifelong delight ; if he love the birds, it transfixes 
them in their flight, yet leaves them to soar in the air 
unharmed. So it is not strange that every one nowa- 




/m>i/'iijL^*:5 




Fig. ioi. — Larva of the Willow Saw-fly. 



days must have a camera to enrich life and to give per- 
manent record to its transitory phases. 

To the student of the teeming insect life that fills the 
outer world with such marvellous organisms, the camera 
may become of inestimable value. It enables him to 
picture phases of their existence so evanescent that it 
is hopeless to attempt to get accurate drawings of them, 
while it furnishes pictures in many ways more satis- 

107 



Nature Biographies. 



factory than the best of artists can make. It is ahvays 
available, and there is comparatively little trouble in tak- 
ing the pictures. Not every one can go a-birding with the 
camera, but most people who so desire can go a-bugging 
with it. And if the " bugs " are gorgeous butterflies or 

resral moths, the 
result both as to 
beauty and inter- 
est is not to be 
despised. 

Theoretically, 
the way to catch 
insects with a 
camera is to take 
it into the field 
with you and ex- 
pose upon them 
as they rest upon 
the leaves or flit 
from flower to 
flower. This is 
entirely feasible, 
and many good 
pictures may thus 
be obtained. 
Such exposures, however, must be very short, and there 
are many things to interfere with getting the best results. 
While some phases of insect life — the flight of a swarm 
of butterflies, for example — are onh' to be taken by such 
outdoor exposures, more satisfactory results are to be 
obtained in the great majority of cases by bringing the 
insects to the studio where you can better control the 
conditions of exposure. The principal advantages you 

1 08 




!"](.. 102. — A Crant'-tly, 



■■■ 



■1 



The Camera and the Entomologist. 



thus have are the control of the light both as to intensity 
and direction, and the ability to use a satisfactory back- 
ground. You also are thus able to rear the insect 
through the different stages of its life, and to get pic- 
tures of each phase of 
existence of the same 
individual. 

Many successful 
photographs of insects 
have been taken by 
professional entomolo- 
gists in insectaries that 
practically are simply 
glass houses, with 
strong light coming 
from all directions. In 
such situations the 
exposures are very 
short, and it is com- 
paratively easy to get 
pictures of insects in 
all stages. The light 
effects, however, are 
usually flat, and the 
details of structure are 
frequently lacking. I 
greatly prefer a very 
different sort of a studio, and have taken most of my 
pictures in a basement room lighted only from one side 
by comparatively small windows, so curtained that the 
light is easily controlled. This, of course, involves longer 
exposures, which in turn give greater detail and much 
more satisfactory results. One great advantage of the 

109 




Fig. 103. — Larva of the Polyphemus Moth. 



Nature Biographies. 



side windows is that the Hght effects are rounded rather 
than flat, so that the form of the insect or plant is more 
distinctly brought out. 

There is also a decided advantage in utilizing a base- 
ment room, or, at least, one near the ground, especially in 

a building in which 
there are other occu- 
pants. The slight- 
est movement of the 
specimens before the 
camera spoils the 
picture, and I have 
found that even on 
the second floor of 
a solid brick build- 
ing the slammino- of 
a door often caused 
such a jar as to set 
the leaves of a plant 
in motion. Under 
the most favourable 
conditions there are 
always enough 
chances of failure, 
so that one does not 
care to run this 
additional risk. 
The length of exposure will depend, of course, directly 
upon the light at the time. I should prefer a room fac- 
ino^ the north, where the lio-ht does not fluctuate so 
greatly through the changing position of the sun, but as 
yet I have had to be content with a room facing the east. 
From 9 a.m. to i p.m. the light in this room is quite sat- 

I 10 




Fig. 104, — Larva of the lu Moth 



mmmmmmmmm 



■■■ 



The Camera and the Entomolog-ist. 



isfactory, varying somewhat from hour to hour. The 
average exposure through the smallest stop and with- 
out the colour screen is about forty-five seconds. With 
the colour screen which is almost indispensable for red 
and red-brown tints, the exposure must be about five 
times as lono^. The best colour screen seems to be the 
ray filter, which contains a solution of bichromate of 
potash, and with which satisfactory pic- 
tures may be obtained of such difficult 
colours as the reds and browns of many 
butterflies. In my experience there has 
been no great advantage in using this 
screen on yellow, green, or whitish tints, 
while, of course, there is the obvious dis- 
advantage of the longer exposure. 

It is comparatively easy to get good 
photographs of the leaf-feeding caterpil- 
lars. Many of them feed mostly at 
night, resting by day in various charac- 
teristic attitudes. At such times they 
remain quiet for hours, so that one can 
focus and expose upon them indefinitely. 
Consequently pictures showing excel- 
lently the details of their structure may be taken ; exam- 
ples may be seen in the larvae of the Polyphemus moth, 
the lo moth, and the willow saw-fly. By placing the 
caterpillars upon a plate of glass against a black back- 
ground, one may get such pictures as that of the larva 
of the Troilus butterfly. 

Many species of caterpillars construct for themselves 
habitations of various kinds. Like the nests of birds, 
however, these domiciles are exceedingly difficult to 
depict satisfactorily by any other method than that of 

II I 




Fig, 105. — Caterpillar 
of Troilus Butterfly. 



Nature Biographies. 



photography. They are generally made of very minute 
silken threads, the effect of which any line of pen or 
pencil fails to portray. But, under favourable conditions, 

perfect pictures may 
easily be obtained with 
the camera. Numerous 
examples of these may 
be found in the pictures 
of the nests of the 
American tent caterpil- 
lar and the cherry tent- 
maker in earlier pages 
of this book, as well as 
in the accompanying 
photograph of the web 
of the fall web-worm. In 
the original photographs 
one can see distinctly 
the different layers of 
silk of which the nests 
are composed. 

All of these three last- 
mentioned insects are 
builders of communal 
homes, but there are 
laree numbers of cater- 
pillars that live singly 
rather than in colonies, 
and these also often con- 
struct protections for themselves. The camera portrays 
such domiciles in a very satisfactory manner. For ex- 
ample, the larva of the beautiful Atalanta butterfly lives 
in nettle leaves, the edges of which it rolls up and binds 

112 




Fig. io6. — Web of Fall Web-worms upon 
an Apple Twig. 



■■■■ 



■■■ 



■■ 



The Camera and the Entomologist. 




Fig. 107. — Leaf Case of Atalanta Caterpillar. 



together by silken threads. Such a leaf, as well as one 
that has been opened to reveal the spiny caterpillar, is 
shown in Figures 
107 and 108. 

The peculiar 
plant growths 
called galls are 
among the most 
interesting prod- 
ucts of insect en- 
ergy. These are of 
many forms, and 
often of very 
curious structure. 
They are generally brought about in this way : an ^<y^ is 
laid on or in the tissue of a leaf or bud ; it shortly hatches 
into a tiny larva which feeds upon the surrounding tissue, 

and by its pres- 
ence causes the 
plant to develop 
an abnormal 
growth. 

The strange 
thing about 
galls is that 
each species of 
insect causes a 
peculiar and 
characteristic gall, so that on a single oak tree there 
may be a dozen sorts of galls, entirely distinct in appear- 
ance, each inhabited by a different sort of an insect. 
In due time the larva within the gall becomes full 
grown; then it changes to a pupa, and later again to an 

113 




Fig, 108. — Leaf Case opened to show Caterpillar, 



Nature Biographies. 

adult. Veiy often there are muUiple gahs, each contain- 
ing many insects. 

Galls are often so complex in structure that it is diffi- 
cult to get satisfactory drawings of them. But this fact 

need not trouble the 
entomologist who uses 
the camera. An exam- 
ple of these galls may 
be seen in the picture 
of the multiple golden- 
rod gall. 

In the case of many 
plant-feeding insects the 
injury done has well- 
marked characteristics 
which enable the ento- 
mologist to tell at once 
what species was at 
work, long after the 
depredators have disap- 
peared. As a rule, it 
is difficult to represent 
such injuries by draw- 
ing or painting in a way 
that will enable one to 
identify them, but with 
the camera this is easily 
done. Take for example the two pictures of the apple 
leaves shown in Figures no and in; these illustrate 
the work of the fall web- worm, the insect whose tent is 
shown in Figure io6. These caterpillars commonly build 
unsightly nests on the leaves and branches of a great 
variety of fruit and shade trees. When young they feed 

114 




Fig. 109. — Multiple Goldenrod Gall. 



L 



■■■ 



■■I 



■ 



The Camera and the Entomolo^^ist. 



only upon the green surface of the leaf, leaving such a 
network of veins as is shown in Figure iio, but when 
nearly full grown, they devour more of the leaf sub- 
stance, eating out the smaller veinlets, but leaving the 
larger ones as shown in Figure iii. Now these are 
interesting and important phases of the life-history 
of this insect, and it is 
of a decided gain to be 
able to illustrate them so 
vividly when one wishes 
to monograph the species. 
Such a picture as Figure 
1 1 2 also illustrates the 
same point : near the cen- 
tre of the leaf, at the right 
of the midrib, is seen the 
remnants of a cluster of 
minute eggs, laid there by 
a good-sized moth. In 
due season these eggs 
hatched into tiny cater- 
pillars that ate the green 
surface of the leaf from 
day to day ; their feeding 
grounds are readily seen 
on each side of the egg- 
shells. But after feeding thus for a week, they migrated 
to new^ pastures on other leaves, their work remaining 
as mute testimony to their presence. 

Another sort of injury to oak leaves is shown in Fig- 
ure 113, which illustrates the work of a small caterpillar 
that sews together adjacent leaves and then feeds wdthin 
the shelter thus made. Sometimes this insect becomes 

115 




Fig. iio. — Apple Leaf denuded by Fall 
Web-worms. 



Nature Biographies. 

so abundant as to sew up a large proportion of the 
leaves. 

If I were required to hmit my use of the camera to 
any one phase of insect hfe, I should choose the transi- 
tion stages between the larva and the adult. For these 
stages are so brief that it is difficult to get good drawings 
of them, and the insect is then in such a condition that 
it is impracticable to preserve it satisfactorily. But with 




Fig. III. — Apple Leaves eaten by Older Web- worms. 

a camera one can focus upon a chrysalis about to dis- 
close the butterfly, and when the insect comes out make 
a series of exposures that will give excellent pictures to 
show the curious process of wing development. Ex- 
amples of this are given in the first two articles in this 
book. 

Attention has already been called, in a preceding 
article, to the fact that beautiful photographs are to be 
obtained by taking advantage of the fact that when a 

ii6 



The Camera and the Entomologist. 

moth or butterfly becomes fully formed after emerging 
from the chrysalis, it rests quietly for about an hour to 
enable its tissues to harden preparatory to flight. In 
addition to the examples already given attention is called 




Fig, 112. — Oak Leaf partially denuded by Caterpillars. 



to Figures 114 and 115 : the former represents the beau- 
tiful Cecropia emperor moth, resting upon its cocoon, and 
the other a back view of the handsome Promethea moth 
in a similar position, most of the cocoon in this case 
being hidden by the body of the insect. With most 
butterflies and moths such a view as this last is rather 

117 



Nature Biographies. 

difficult to get, as they commonly rest at this time with 
their wings closed, opening them only for very brief 
periods. 

In attempting to get pictures of adult insects brought 
to the studio from out of doors, it is best to brino- the 




Fk;. 113. — Oak Leaves sewed together by (Caterpillars. 

subjects in at least a day before you wish to photograph 
them, and to surround them with as natural conditions 
as possible. Thus they become so used to the new 
environment that they will remain quiet when you make 
the exposure. Good pictures of katydids and related 
insects may be often obtained in this way. Some- 

118 



■■■■Hi 



■■■ 



mmmM 



The Camera and the Entomologist. 



times on rainy clays 
you will find various 
sorts of wasps and 
bees resting quietly 
under the shelter of 
flowers. By careful 
handling, these may 
be brought to the 
studio and pictures of 
them secured. 

One of the most suc- 
cessful photographs 
I have taken of an 
insect not reared in 
captivity is the crane- 
fly, shown in Figure 





Fig. 115. — Promethea Moth resting on Cocoon. 

119 



Fic. 114. — Cecropia Moth resting on Cocoon. 

102, which wan- 
dered into the 
studio of its own 
accord. This 
insect looks like 
a gigantic mos- 
quito ; it is com- 
mon in meadows 
and near water- 
courses during 
summer. An- 
other such pic- 
ture is shown in 
Figure 117; this 
dragon-fly had 
flown indoors 
in late autumn, 



Nature Biographies. 

having been chilled by the cold, and it was so stupefied 
that it would rest quietly while its picture was taken. 

The camera can also be used to advantage in taking pic- 
tures of dead insects, not necessarily the unattractive illus- 
trations of pinned insects, so often seen in entomological 




Fig. 1 1 6. — The Luna Moth. 

bulletins, but rather pictures made from fresh unpinned 
specimens that similate the living insect. Such a picture 
of the beautiful Luna moth is shown in Figure ii6. 

These camera studies of insects require patience and 
perseverance for the most successful results. It is a 
comparatively new field of photographic activity, but one 

1 20 



mmm 



The Camera and the Entomologist. 

in which the naturaHst will be richly rewarded. It 
seems certain that future books on insects will be illus- 
trated chiefly by means of photographs, so that entomo- 




?nr 



"m^rrrmmma^ 




Fig. 117. — A Dragon-fly. 

logical literature will have a new and fresher interest to 
every one who loves even the ephemeral things of the 
outer world. 



121 



STUDIES OF INSECT PARASITES. 



A PARASITE OF COLONIAL CATERPILLARS. 




One day last summer I found upon 
an apple leaf a colony of small red- 
dish caterpillars. When not eating, 
they rested together on the under 
surface of the leaf; when eating, they 
congregated along the outside and 
devoured the margins. The insects 
were recognized as young specimens 
of the Red-humped Apple Caterpil- 
lar, which, when full grown, is pictured above. They 
were brought to the laboratory in order to rear them. 

Throughout their larval 
existence these insects 
remain together in colo- 
nies, feeding voraciously 
upon the foliage and de- 
nuding the branch as they 
proceed. On this account 
the injury they do is 
easily noticed, and when 
noticed the caterpillars 
are easily destroyed. If 
they are not destroyed, 
they descend to the ground 
when full g^rown, where 




Fig. ii; 



Part of Colony of Red-humped 
Caterpillars. 



122 



Studies of Insect Parasites. 



under leaves or other shelter at or just beneath the soil 
surface they construct fragile cocoons. In these they 
pass the winter, maturing the following summer into 
medium-sized brown and gray moths. 

The caterpillars that I brought to the laboratory, 
however, were destined to have no such life-history. A 
day or two after I found them 
I noticed that the leaf on 
which they were was not 
being devoured; on looking 
at its under surface I found 
that every caterpillar had 
given place to a small cocoon 
formed inside its skin and 
having the head and legs of 
the larva still in position. It 
was, indeed, a strange sight ; 
not one of the larvae had 
escaped. 

It was easy enough to un- 
derstand what had happened 
to my little colony. Some- 
time before I found them, a 
small four- winged fly had 
been among them. Perhaps 
she had thought herself lucky 
to find so many victims near 

together, so that she could dispose of so many eggs 
without the trouble of hunting out lonely caterpillars. 
At any rate she deposited an Qgg in each of the larvae 
and then left the colony to its fate. Each egg shortly 
hatched into a minute maggot that fed upon the fatty 
tissues of its host, finally leaving nothing but the skin, 

123 




Fig. IK 



The Parasitized Colony. 



Nature Biographies. 




and thus reaching the hmit of its food-supply. It then 
spun a cocoon around itself, the outside of the cocoon 
being consequently covered by the skin of the late host. 
The lower part of the skin generally splits apart longi- 

tudinally so that 

I the cocoon rests 
|_ upon and is at- 
tached to the leaf. 
Within this cocoon 
the maggot changes 
. _^ ' to a pupa, and a 

y*, little later it again 

chano^es to an adult 
four-winoed ichneu- 
mon-fly, which is 
called by entomolo- 
gists Linineria fti- 
gifiva. 

In choosing its 
victims this Limne- 
ria by no means con- 
fines itself to these 
red-humped apple 
caterpillars. Early 
in the season it very 
commonly attacks 
young American 
tent caterpillars, in 
the empty skin of which it makes its cocoon in the 
same manner, while later in the season it attacks the 
larvae of the fall web-worm and various other species. 
It seems to prefer those species that live together in 
colonies. 

12 A 




I 



Fig. 1 20. — Colony of lo Caterpillars upon a Com- 
pound Leaf. 



Studies of Insect Parasites. 



The colonies of the larvae of the lo moth are also 
attacked by this parasite, notwithstanding the spiny cov- 
ering of the caterpillars. These lo larvae feed upon the 
leaves of quite a variety of trees, shrubs, and herbaceous 
plants. The larvae go to and from their feeding places in 
single-file processions. When 
not feeding they rest together 
on the lower side of a leaf in 
groups of a dozen or more. 
This habit is well illustrated 
in Figure 120, which shows 
a compound leaf on which the 
caterpillars have been feeding, 
while the colony has divided 
itself for resting into two com- 
panies of nearly equal numbers 
that have stationed themselves 
on two of the whole leaflets 
that remain. In Figure 121, a 
similar colony is shown, larger 
size, upon an apple leaf. 

The habit of thus congregat- 
ing is probably a help in pre- 
venting the attacks of birds, 
especially in the case of such 
spiny species as these lo larvae. 

But it is a decided advantage to the Limneria parasites. 
With a colony of young los brought to the laboratory on 
a poplar twig I had just such an experience as I have 
recorded above in the case of the red-humped caterpil- 
lars. The skin of every larva in the lo colony shortly 
became occupied with a Limneria cocoon, showing that 
they all contained the parasites when they were found. 

125 



m 


1 


s^^B^ 




! 


^^^■i^DA 


1 








1 


' 



Fig, 121. — lo Caterpillars upon an 
Apple Leaf. 



Nature Biographies. 

These Limneria larvae do not always have things their 
own way, however. They are very commonly subject to 
the attack of another parasite that destroys them as they 
destroyed their hosts. So it often happens that if you 
bring in from out of doors a colony of the Limneria 
cocoons, the adult flies that come from them may be a 
species of Pimpla instead of Limneria. In this case the 
Pimpla is said to be a secondary parasite of the original 
host, that is, it is a parasite of the parasite. And not 
uncommonly there is a tertiary parasite that destroys 
the Pimpla larva as it destroyed that of the Limneria. 

A PARASITE OF BUTTERFLY EGGS. 

One bright May morning while I was walking along 
a picturesque byway with the Little Lady who helps me 
to see what is going on, we found a mourning-cloak 
butterfly in the act of depositing her eggs on a willow 
twig. She had already deposited about twenty eggs in 
a circle around the stem, and continued at work as we 
bent over her in eager observation. We saw a small 
gray hunting spider wandering around on the wings of 
the butterfly, apparently without her knowledge, for she 
paid no attention to him. After about five more eggs 
had thus been laid the Little Lady's hat brushed against 
the butterfly, which then flew away. The instant she 
had gone, we saw a tiny four-winged fly running excit- 
edly about upon the eggs. I was delighted, for I saw 
that in all probability we were to have a glimpse of 
another bit of insect domesticitv, — not unmixed with 
tragedy, — and I was not disappointed. For in a few 
seconds the tiny fly stopped over one of the butterfly 
eggs, held its body up vertically with its hind legs back 

126 



■■■■■■■■■■■■■■ 



Studies of Insect Parasites. 

of it, and its other legs straightened out to hold the 
front of the body high up, and having inserted its tiny 
ovipositor through the egg, proceeded to deposit an Qgg 
of her own inside of the larger egg of the butterfly, 
that is, I assume that this was what happened, although 
of course it was impossible to see the smaller egg as it 
was laid inside the shell of the larger one. While thus 
engaged the antennae of the tiny fly were bent directly 
downward to the egg beneath. In about a minute the 
fly withdrew its ovipositor, and after running around for 
a few seconds, again settled down upon another egg and 
repeated the operation. Soon it tried again on a third 
egg, and I saw that the domestic scene was likely to be 
continued for some time. So I quietly cut off the 
twig without disturbing the little creature, and sat down 
by the roadside, asking the Little Lady to keep the record 
that as timekeeper I dictated. This is her record : — 



t required 94 seconds 


to lay egg No 


4 


Then fly moved around 26 


120 " 


" "• " " 


5 


U .4 u 


27 


u . 83 u 


U .i .. u 


6 


u u a 


20 


.. " 92 - 


u u a a 


7 


u u a 


22 


" " 75 


ki a k4 .i 


8 


ii u u 


40 


u u ^0 u 


u .4 a U 


9 


ii. a a 


42 


" " 102 


'• "• " " 


10 


a a ii 


' 15 


u ,20 " 


'' " 'V ■" 


II 


a a ii 


' 21 


u u J 20 " 


it a a a 


12 


ii ii a 


18 


60 


a u ib a 


13 


i, ii ii 


- 25 


120 


" '' •' 


14 


ti ii a 


' 25 


60 


" « 


15 


a a a 


50 



seconds. 



Thus the deposition of these fifteen eggs had occupied 
something over half an hour. By this time both recorder 
and observer were tired of sitting in the hot sunshine and 
we were also afraid the little fly would escape. So I sacri- 
ficed her to the cause of science, and later sent her to 

127 



Nature Biographies. 

Dr. L. O. Howard, the United States entomologist and 
our greatest authority on these tiny parasites, who kindly 
identified her as belonging to the species Telenomus 
gi^aptce, whose life-history was briefly outlined in the 
article treating of the Antiopa butterfly. 

What interested me most in this bit of tragedy was 
the sudden appearance of the Telenomus fly upon the 
scene. As already stated, she was running over the eggs 
the instant the butterfly flew away, and very likely she 
had been there before and had not been seen because 
our attention was taken by the butterfly. How did this 
tiny creature, scarcely as large as a pinhead, happen to 
be present on that particular twig at that particular 
time .f^ In the region there w^ere hundreds of thousands 
of other twists on which no es^ors were beino: laid. Has 
the fly a perception of odour so keen that it can detect 
fresh-laid butterfly eggs at great distances, or does it 
light upon the body of the butterfly and rest there until 
she deposits her eggs ? 

A few weeks later I was in New York attending a 
meeting of entomologists and related this experience. 
When I had finished Professor C. W. Woodworth, the 
entomologist of the University of California, told of a 
similar experience years before in the White Mountains 
of New Hampshire. His Telenomus had been seen 
as mine had, engaged in ovipositing as soon as the eggs 
were laid. 

A MOTH THAT FAILED. 

Last October I found a large green Sphinx caterpillar 
upon the under side of a willow leaf. I put it in a box, 
thinking to rear it to the beautiful moth into which in the 
usual course of nature it would change. The box w^as 

128 



■MMMHHH^MMIH^I^HHHHiHHH 



Studies of Insect Parasites. 

left in the carriage over night ; when I came to look 
for the insect the next morning, it had escaped from its 
prison and was, I supposed, lost. But happening to 
look in the bottom of the carriage I found my prisoner 
in a hapless plight. It was resting on the edge of the 
mat, and w^as covered and surrounded with a mass of 
small w^hite oval objects, most of them attached to the 
caterpillar, but many attached to the board on the bot- 
tom of the carriage. 

The caterpillar was half dead, without sufBcient strength 
lo crawl away from the encompassing cocoons. For these 




Fig. 122. — Sphinx Caterpillar with Cocoons of Parasites. 

were the cocoons of parasites. The little creatures that 
made them had come from inside the caterpillar. Their 
previous history was simply this : one day, a few weeks 
before, a small black four-winged fly had alighted on the 
larva, probably as it was resting upon the back of the 
willow leaf, and had inserted beneath its skin, by means of 
a sharply pointed ovipositor, a large number of tiny eggs. 
I suppose that these eggs are deposited one in a place, 
so that they are scattered about different portions of the 
body, near the surface, but I have never been so fortunate 
as to see the fly in the act, nor have I read any record of 
any one else having done so. 

129 



Nature Biographies. 



The eggs soon hatch into tiny footless maggots that 
derive their nourishment from the fatty tissues of their 
host. They increase gradually in size for a short time. As 
they approach maturity they have the appearance of Fig- 
ure 122^. As is the case in general with the early stages 
of parasitic insects, the structure is very simple. As will 
be seen there are no signs of legs, the body consisting of 
segments, growing smaller toward the pointed head, and 
ending behind in a large rounded joint. 
The alimentary canal is simply a tube 
closed at the posterior end. There 
are no eyes, and the outer skin is un- 
coloured. 

When these creatures are full grown 

in this their larval state, they all leave 

their unfortunate host at the same time, 

burrowing through the skin. As soon 

as they are outside, each begins spinning 

the delicate silken shroud that serves 

as cocoon, completing it within a few 

hours. Inside of these they shortly 

change to tiny pupae, and a week or so 

later again change to four-winged flies. 

The latter are provided with sharp jaws by means of 

which each cuts off a lid from the end of the cocoon, 

and escapes. 

The poor, half-dead caterpillar that thus became an 
unwilling sacrifice, giving up his own existence that a 
hundred or more lesser creatures might live, finally died 
and shrivelled up, never becoming the beautiful moth 
into which it might otherwise have changed. 

People frequently bring me small yellow cocoons 
attached in loose masses to the stems of grasses, clovers, 

130 




Fig. 122 a. — Larva 
of Microgaster Fly, 
much magnitied 
(after Leuckart). 



Studies of Insect Parasites. 



and other herbaceous plants. Late 
in summer and early in autumn one 
may commonly find such masses in 
pasture fields and meadow-lands. An 
idea of their appearance may be gained 
from Figure 123, which represents them 
slightly magnified. 

These cocoons have a history very 
similar to that of the cocoons upon 
the sphinx larva just described. The 
insects within them have developed 
at the expense of some grass or clover- 
feeding caterpillar, which they have 
killed, and then attached their cocoons 
to the nearest support they could find. 
Probably the larvae of the common 
yellow Philodice butterfly are most 
frequently thus victimized, but cut- 
worms, army-worms, and other grass- 
feeding caterpillars often suffer also. 




Fig. 123. — Cocoons of 
Microgaster Fly. 



131 



INSECTS IN WINTER. 




One of the truisms of modern biology 
is that every species of animal exists 
by virtue of its adaptations to the con- 
ditions of its existence. The study of 
these adaptations forms a large part 
of the work of the latter-day naturalist, 
who is led again and again to wonder 
at the perfection of the adjustments 
that he discovers between animals 
and their surroundings. 
In northern regions adaptation to climate is one of the 
most important problems that confronts each species. 
Those animals that like the birds can migrate quickly to 
warmer regions easily solve the problem, but those that 
must remain in one region throughout their lives find 
the solution more difficult. In the case of many of the 
insects there are four distinct staQ:es of existence in which 
the winter may be passed, so there is considerable oppor- 
tunity for variation as to the method of hibernation that 
may be chosen, through the action of natural selection, 
which must take into account not only the cold weather, 
but also the many enemies abroad during this period. 
For to these insects death may come at any hour between 
November and April. His grim messenger may ride on 
the wings of the wind and carry them far from food, so 
that if they survive until spring starvation awaits them. 
Or he may fall with the rain and wash them into pond,, 

132 



■1 



IH 



Insects in Winter. 

lake, or sea, or come with the snow and bear them away 
in whitened arms. Or perchance he may choose the 
winter birds to carry his message, sending destruction 
through the beak of nuthatch, or woodpecker, or chicka- 
dee. And during the periods immediately preceding 
and following cold weather he may choose to do his 
errands, the myriad predaceous and parasitic insects that 
live only at the expense of the lives of unwilling hosts of 
their own class. 

To contend with death in all these forms is no light 
matter. And were it not that each insect brings to the 
fray the unconscious wisdom derived from the experience 
of countless generations of ancestors, it were a hopeless 
one. But during all the ages each species has been ad- 
justing itself more and more perfectly to its surround- 
ings, increasing its means of protection from the primal 
elements, perfecting the disguise which conceals it from 
living enemies, or if these means avail not, increasing its 
rate of reproduction to such an extent that the 999 may 
perish and the one continue to propagate the species. 

This long-continued struggle for existence has brought 
about many curious adjustments in the insect world. To 
our unseeing eyes the hosts of insects abroad during the 
summer months seem wholly to disappear when winter 
comes. The question as to where they go is often asked. 

If we look about us to see where it is possible for 
insects to find shelter during winter, we see that at least 
the following locations are available: in the ground, 
or under shelter on its surface ; in ponds, streams, and 
other bodies of water; in stumps, logs, and dead wood 
and plants of all sorts ; in or on living trees, shrubs, and 
smaller plants ; in galls ; in fruits ; and in occasional 
shelter provided by man for his own service. 

133 



Nature Biographies. 



Insects may hibernate in each of the four stages of 
their existence. As a rule, each species passes the winter 
in but one of these stao^es, ahhou2:h occasionally an in- 
sect will be found hibernating in two or possibly three 



stages. 



In o-eneral, the hibernatino^ stao:e is the one in 



which the insect underQ-oes the least risk durino; the 



winter. 



I. THE EGG. 




When we consider the small size of the egg as com- 
pared with the other stages of an insect's life it would 
seem that there might be many advantages to the species 
in hibernating in this condition. And in truth a great 
many insects do utilize this stage for passing the long 
months of danger; excellent examples have already been 

discussed in the 
two species of tent 
caterpillars, the 
cherry tent-maker, 
and the walking- 
stick. And appar- 
ently the orders 
Lepidoptera and 
Orthoptera to 
which these insects belong contain a larger proportion 
of common species that hibernate in the egg state than 
do any of the others, except, perhaps, that of the true 
bugs — Hemiptera. 

In the order Orthoptera hibernation in the egg state 
is the rule rather than the exception. Besides the 
walking-stick already mentioned and the various spe- 
cies discussed in the following paragraphs, the cock- 
roaches, praying mantes, black crickets, and tree crickets 
all hibernate as eggs. This is probably due to the com- 

134 



Fig. 124. — The Pine Locust, Male, slightly magnihed. 



Insects in Winter. 



paratively large size of the members of this order and 
the eagerness with which they are devoured by birds, to- 
gether with the fact that most of them depend for food 
upon herbaceous plants, and rely for protection upon 
their resemblance to these plants. 

Most of our common grasshoppers, or locusts, hiber- 
nate in the egg state in the ground slightly beneath the 
soil surface. There is at least one species,^ however, 
common in New 
England, that 
deposits its eggs 
in soft wood. 
One bright Oc- 
tober day I hap- 
pened to come 
across a fence 
beside a bit of 
woods, in the 
posts of which 
these locusts 

were busily laying their eggs. On the top of nearly 
every post was one or more of these busy creatures 
with her abdomen thrust down into a crack or crevice 
where she was depositing her bunch of eggs. The posi- 
tion then assumed is well shown in Fio-ure 126, which 
was the only fairly successful result of several attempts 
to photograph one of the insects while ovipositing, the 
fact that they move their bodies constantly up and down 
making the taking of the picture difficult. The shape 
of the end of the abdomen in the female grasshoppers is 
shown in Figure 125; as will be seen it is pointed at 
the end, a fact which easily distinguislies this sex from 

^ Melaiioplus punctulatits. 




Fig. 125. — The Pine Locust, Female, slightly magnified. 



Nature Biographies. 



the smaller males, which have the end of the abdomen 
rounded (Fig. 124). This species appears to have be- 
come adapted to life in open pine woods ; it is coloured 
in mossy grays and browns that help to conceal it when 
upon the bark of trees or logs. 

These grasshopper eggs, whether laid in w^ood as with 
the species illustrated, or in the ground as with most of 
the field species, remain unhatched until the following 
spring. During this long period they are subject to at- 
tack from a host 
of enemies, in- 
cluding birds, 
predaceous in- 
sects, and small 
red mites that 
feed freely upon 
the Qgg contents. 
Those eggs 
which are not 
destroyed before 
the latter part of the following spring hatch into young 
hoppers that feed upon the tender foliage of grasses or 
other plants. 

These common grasshoppers belong to the family 
Acrididae. They are chiefly distinguished from the 
Katydid family (Locustidae) by their short antennae, 
these organs in the latter being long and slender. The 
Locustids generally Liy their eggs above ground, the 
precise situation varying with the species. Some of the 
typical katydids oviposit upon the twigs of trees, the eggs 
being flat, oval objects. The method of oviposition 
of the angular- winged katydid has been described by 
Dr. C. V. Riley in these words: "Selecting a twig of 

136 




Female Locust depositing Egg Mass. 



Insects in Winter. 



about the size of a common goose-quill, this provident 
mother prepares it for the reception of her eggs by 
bitino- and rouohenino- the bark for a distance of two or 
three inches. This bite is not gradual like that made 
when feeding, but is sudden and vigorous, the insect 
chewing and pressing the twig each side so as to form 
an edge. This operation is 
accompanied by a sudden 
nervous shake of the body 
from side to side, and lasts 
sometimes but two or three 
minutes, sometimes more 
than ten. When the opera- 
tion is accomplished to her 
satisfaction, she clutches with 
her front feet the stem to be 
used, and anchors the middle 
and hindmost feet for the 
most part upon contiguous 
leaves or branches, and often 
quite wide apart. Then, if she 
has her head in an upward 
direction (for it seems to be 
immaterial to her whether the 
eggs are placed from below up 

or vice versa), she begins at the lower end of the rough- 
ened portion of the twig, and after fretting it anew with 
her jaws and measuring and feeling it over and over 
again with her palpi, as if to assure herself that all is as 
it should be, she slowly — with much apparent effort, and 
not without letting it partly fall several times — curls the 
abdomen under until the lower edge of the curved ovi- 
positor is brought betw^een the jaws and palpi, by which 

137 




Fig. 127. — A Common Katydid. 



Nature Biographies. 

it is grasped and guided to the right position. It is then 
worked sHghtly up and down for from four to six min- 
utes — ah the time guided by the jaws, — while a shiny 
viscid fluid is given out apparently from the ovipositor. 
Finally, after a few seconds' rest or suspension of this 
work, the Qgg gradually rises, and as it passes between 
the ovipositor turns so that the one end appears almost 
simultaneously from betw^een the convex edge with the 
other from the lower tip of the blades. The egg adheres 
to the roughened bark in an oblique position. 

" After the tgg is placed the abdomen is straightened 
out and the insect rests for a few moments, soon, how- 
ever, to resume her efforts and repeat the like performance 
in every particular except that the second egg is placed 
on the opposite side of the twig and a little above the 
first one. The third egg is pushed in between the top of 
the first one and the twig, the fourth between the top 
of the second and so on, one each side, alternately. 
Thus these eggs are not laid as we might naturally 
infer, one over the other, but rather one under the 
other, that is, each succeeding pair having their ends 
thrust in between the tops of the preceding pair, the 
teeth at the end of the ovipositor helping to crowd 
the end into place." 

The pine-cone willow-gall is described on a later 
page as the home of certain larvae of two-winged flies. 
An examination of these galls in winter will often reveal 
another occupant ; between the plates will be found 
rather large, elongate, yellowish eggs. These are too 
large to belong to either of the flies which commonly 
inhabit the gall. They are, in fact, the eggs of a meadow 
grasshopper (a member of this Locustid family), which 
has learned to take advantage of these galls as a place 

138 



■■■■■■I 



Insects in Winter. 

for egg deposition. It is an excellent plan from the point 
of view of the grasshopper, for it is easy to insert the 
eggs, and they are safely protected through the winter. 

In the order of true bugs — Hemiptera — there are 
many species that pass the winter in the tgg state. 
With two of the largest families — those of the plant- 
lice and the bark-lice — this may fairly be considered 
the normal method of hibernation, while throughout the 
order it is common with many species. 

If you look carefully through a hand lens at the twigs 
of apple trees, you will often find on the buds or at their 
bases small, black, smooth, shining, oval objects : these 
are the eggs of the apple aphis. They were deposited 
the previous autumn by the wingless female aphids, and 
will hatch the following spring into other female aphids. 
The latter will crawl upon the unfolding leaves, insert 
their tiny beaks into the tissues, and suck the sap. 
They develop rapidly, and in two weeks or so become 
full grown. Each then begins giving birth to living 
young, a process which continues through successive 
generations throughout the summer until in autumn 
a sexed generation is produced ; the winter eggs are 
deposited by these. 

A considerable variety of aphid eggs may be found in 
winter on the bark of willow shrubs. Some of these are 
deposited about the buds, in which case they may belong 
to one of several distinct species. Others are to be seen 
thickly scattered over the general surface of the bark, as 
shown in Figure 129; these are likely to belong to a 
rather large species of the genus Melanoxanthus. Gen- 
erally these eggs are more or less covered with a whitish 
substance that makes them less conspicuous upon the 
light gray bark. 

139 



Nature Biographies. 

These plant-hce are attended by black ants until the 
very end of the season. Throughout last October, and 
even on sunny days in November, the ants were busily 
running about among the aphid colonies, caressing the 
insects with their antennae as shown in Figure 128. 

All of these aphid eggs attached to the surfaces of 
trees, shrubs, and plants are liable to many dangers. 
Unless they are securely fastened, they may be blown 
or washed away, or in time of sleet and ice they may 
be torn from their support. They also furnish a large 
percentage of the food of winter birds, like the chicka- 




FlG. 128. — Ants attending Willow Aphides. 

dees and nuthatches. In a recent study of the winter 
food of the chickadee in New Hampshire I found that 
more than one-fifth of it consisted of the eggs of plant- 
lice. As many as 450 of these eggs were sometimes 
counted from a single stomach representing not more 
than one day's food. Probably only a very small pro- 
portion of the eggs that are laid in autumn survive to 
hatch in spring.^ 

On the bark of apple twigs one may commonly find 
small grayish or brownish scales about one-tenth of an 
inch long, shaped something like a miniature oyster 

1 In my Life Histories of American Insects I have given a rather full 
discussion of the hibernation of aphids (pp. 209-247) ; consequently I omit 
further reference to this interesting group in this connection. 

140 



mmmtmmmmmmmmimKaM 



Insects in Winter. 



shell. In colour they generally resemble the bark, so 
that it is easy to overlook them. This is the oyster- 
shell bark-louse, an insect that has long been known 
as a destructive enemy to apple trees. 

If in autumn, winter, or early spring you remove one 
of these scales and examine its under sur- 
face through a lens, you will probably find 
small white objects which are the eggs of 
the bark-louse ; they were deposited beneath 
the scale late in summer by the mother 
insect, whose shrivelled remains are to be 
found at the base of the scale. 

Late in May or early in June these eggs 
hatch into little whitish, six-legged creatures 
with flattened bodies, barely visible to the 
naked eye. These crawl about over the 
bark for a few days. Then they settle 
down by inserting their tiny beaks through 
the bark, generally choosing twigs of the 
previous year's growth. When once set- 
tled, they remain in position and gradually 
begin to form the scale that is so prominent 
in autumn. As the weeks go by the scale 
enlarges until by the end of summer it is 
of full size. Then the mother insect fills 
it with her eggs and dies, her shrivelled 
remains staying in place to help protect the 
eggs through the long winter months. 

Scattered here and there among the larger scales you 
are likely to find smaller ones of a different shape. These 
are the scales of the male insects. 

In the great order Lepidoptera, a considerable number 
of moths hibernate as eggs. Typical examples are found 

141 



Fig. 129. — Eggs 
of Aphides on 
Willow Bark. 



Nature Biographies. 



in the American and forest tent caterpillars and the 
cherry tent-maker discussed in previous pages of this 
book. Other examples are seen in the tussock moths 
of the genus Orgyia. The commonest species is the 
white-marked tussock moth,^ the eggs of which may be 

frequently found dur- 
ing the fall and win- 
ter months upon the 
trunks and larger 
branches of elm and 
maple trees. They 
occur as whitish 
patches, easily visible 
some distance away; 
on closer examina- 
tion these patches are 
found to consist of 
thin, gray cocoons, 
attached to the bark, 
partially covered with 
glistening white 
masses suggestive of 
a dried frothy sub- 
stance. When broken 
open these masses are 
seen to consist of hundreds of small, white, spherical eggs, 
held together by the frothlike substance that permeates 
the whole mass. If the cocoon itself be pulled apart, 
there will be found within it an empty brown pupa case 
from which a moth has emerged. In spring these eggs 
hatch into the tussock caterpillars. 

Another of these moths, the Antiqua Tussock moth,^ 

^ Orgyia antiqua. ~ Orgyia leucostiguia. 

142 




Fig. 130. — Eggs of Antiqua Tussock Moth. 



wmmmm 



wmmmmm 



Insects in Winter. 

seems commonly to choose a dried leaf hanging to a 
twig for her eggs. The egg mass of one of these 
insects as it was found upon an apple tree is shown 
in Figure 130. 

Notwithstanding the immense number of species to 
be found in the three great orders that include the flies, 
the beetles, and the ants, bees, and wasps, it seems that 
very few of them pass the winter in the egg state. 
Apparently, most of them have found one of the three 
later stages more profitable for hibernation. 

n. THE LARVA. 

There is such infinite variation in the larval stage of 
insects that it is not surprising that many species have 
become adapted to hibernation in this condition. The 
proportion varies greatly, however, with the different 
orders. In the Orthoptera, which as already stated 
winter so largely in the egg state, there are very few that 
nibernate as nymphs, or immature forms. The most 
conspicuous examples are certain grasshoppers or locusts 
(Acrididae), which may often be found in a half-grown 
condition. In the Hemiptera there are certain plant-lice 
that hibernate in a very early stage, and various other 
species pass the winter as nymphs, but most members of 
the order seem to hibernate either in the egg or the 
adult state. 

When w^e come to the great order Lepidoptera, how 
ever, we find that many moths and butterflies utilize the 
larval stage for the purpose of hibernation. The ex- 
amples of this are so numerous that I can cite only a few 
of the more interesting or familiar ones. 

The beautiful butterflies of the genus Argynnis are 

143 



Nature Biographies. 




very common in summer, and attract much attention as 
they hover about beds of dogbane and milkweed blos- 
soms. The way in which they pass the winter is of 
pecuhar interest. The eggs are laid in August on the 
leaves and stems of violets ; they soon hatch into small 
larvae that as a rule have the instinct not to eat but to 
take a position on the underside of the leaf and to 

remain there until the following 
/ spring, a seven months' fast that 

seems curious enouoh. When 
the season opens, they feed upon 
the leaves of the violet, maturing 
into butterflies during June and 
July. 
: Late in autumn and early in 

,' spring one of the best sorts of 

situations for the insect collector 
to search is beneath boards or 
• pieces of wood of any sort lying 

vk* ^ ^^ upon the ground. Along fences 

H^ \ and roadsides or in the grass- 

lands he is thus likely to find a 
great variety of insects, includ- 
ing many of the smooth-skinned, 
soft-bodied larvae which are commonly called cutworms. 
These larvae hatched late the previous summer from eggs 
laid by night-flying moths. They feed upon grasses or 
other succulent plants until the approach of cold weather. 
Then they seek the shelter of the board or fence rail, or 
else burrow into the soil. When spring comes, the 
hungry, half-grown worms begin feeding again, eating 
grass or clover, or if some other crop takes the place 
of these, attacking that instead. After a few weeks of 

144 



Fig, 131. — An Argynnis Butterfly. 



■■■ 



Insects in Winter. 



this spring feeding, these cutworms become full grown. 
Making a cell in the earth, they pupate and soon emerge 
as dull-coloured, night-flying moths. 

On the hanging leaves of oak, apple, and some other 
trees, one can often find the mines of some of the leaf 
miners (Fig. 132). Or in autumn when the leaves first 
fall such mines may easily be seen in the leaves upon the 
ground. A careful exam- 
ination of such a leaf mine 
is likely to reveal a larval 
ininer ; for a large propor- 
tion of these insects pass 
the winter as full-grow^n 
larvae within the mine in 
which they have devel- 
oped. In spring they 
change to pupae to emerge 
soon afterw^ard as moths. 

Only a person with very 
shaip eyes need look for 
the winter stage of a com- 
mon injurious insect 
called the bud worm. 
This is a tiny brown cat- 
erpillar that feeds upon 
the surface tissue of apple leaves in summer. When it 
passes its third moult, it knows instinctively that it is 
better to prepare for hibernation, even though the winter 
season may yet be distant. So it wanders to the bark of 
the twig or branch, and seeks some tiny crevice in the 
bark. Here it ensconces itself and spins a tiny case, or 
hibernactclum, just large enough to hold its body. The 
case is sometimes so covered with particles of bark that 

145 




Fig. 



Mine of Leaf Miner in Apple 
Leaf. 



Nature Biographies. 

it is very like the rest of the surface, and in general it is 
so inconspicuous that it can be found only by the most 
careful examination. 

In spring the little caterpillars emerge from these 
hibernacula and seek the openmg buds. They feed 
within these upon the tender tissues of the unfolding 
leaves, which they sew together more or less by means 
of silken threads. In six or seven weeks they become 
full grown as larvae. They now pupate in a cocoon 
made of leaf and silk. About ten days later they 
again change to small moths. 

In the development of this insect there have been 
many opportunities for the working of the laws of natu- 
ral selection. In case the larvae remained on the leaves 
for hibernation, what would happen? In case the larvae 
spun their winter cases on smooth bark, or of colours 
which did not blend with the surroundings, what would 
happen ? 

I have found in the stomachs of chickadees, winter 
cases either of this bud worm or some other larva hav- 
incr a similar hibernatino^ habit. Doubtless other winter 
birds — like the creepers, woodpeckers, and kinglets — 
also eat such morsels whenever they are to be found. 
What effect would this persecution have in perfecting 
the decree of concealment of the winter cases ? 

In the great order of two-winged flies, the Diptera, 
there are numerous species that pass the winter in the 
larval condition, although comparatively few of them 
are easy to find at this season. Those that live in galls 
are perhaps the most accessible ; two examples will 
suf^ce for our present purpose. 

The oval willow twig gall ' is one of the most interesting 

1 Cecidomyia s alias. 
146 



■■ 



Insects ill Winter. 



forms of galls and also one of the most generally acces- 
sible. It is very commonly found over most of the United 
States and will be easily recognized from the sectional 



iew in Fioure 



JO- 



Generally it is nearly an inch long 



P 



and not quite half an inch in diameter. The outside is 
of the reddish colour of the willow bark, becoming darker 
at the beaklike tip. This beak is brittle 
and easily broken off. 

If you cut open one of these galls verti- 
cally so as to disclose the middle, you will 
find the condition pictured. Beneath the 
outer bark is a mass of woody tissue which 
does not show the layer upon layer struc- 
ture that a section of a twig usually reveals. 
Inside it there is a longitudinal channel 
with a smooth and fragile lining. If the gall 
has been opened carefully, and it is winter 
or early spring, you are likely to find within 
this channel a small, orange-coloured mag- 
o[ot, one-fifth of an inch in length. fig. 133. — Sectional 

rj^. . ^ • ^1 • . View of Oval Wil- 

1 his orange maggot is the proprietor lo^.p^n 
of the gall. To serve its purpose the 
willow plant has built the gall and furnished the plant 
juices that have been its food. The maggot has also 
used the gall for its winter quarters, and had it not been 
disturbed would have pupated therein. If you keep a 
lot of these galls under observation in spring, and open 
one frequently, you may be able to see the pupa. 

You will have noticed that the central channel is open 
clear to the tip of the cone. A little study will show you 
that this beaklike tip is evidently the remains of a blighted 
bud. When the pupa is ready to change to a fly it wrig- 
gles to the open end of the channel, and pushes part way 

147 



Nature Biographies. 

out Then the pupal envelope breaks open and the small 
gnatlike fly emerges. 

One of the most curious plant growths is the so-called 



pme-cone willow 
twigs (Fig. 134). 



It 




easily found on the ends of willow 
looks a miniature pine-cone some- 
what compressed longitudinally. 
If you cut through its vertical 
length so as to disclose the mid- 
dle, you will probably find a sort 
of a tube in which is a small 
whitish larva, without legs or feet, 
and with no definite body divi- 
sions. 

How did this larva come to be 
in th'G situation? And what is 
the origin of this remarkable 
growth on the willow stem ? 
Obviously it is not the seed cone 
of the willow, for the seeds of the 
plant are scattered in spring from 
the ripened w^oolly catkins. Per- 
haps you can answer the ques- 
tions better if you find out what 
becomes of the larva. This is 
not difficult. In early spring 
place some of the galls in a glass 
jar. Look at it occasionally ; 
some day you will find some tiny tw^o-winged flies in the 
jar. They look a good deal like mosquitoes. These are 
what the footless larvae have developed into. 

Now if out of doors these flies were let loose, and 
your eyes were keen enough to follow them in their 
flight, you might see some of them search out the 

148 



Fig. 134. — The Pine-cone Wil 
low-gall with Dragon-fly rest 
ing upon it. 



JL 



■■ 



■■■■■^■■i 



Insects in Winter. 

terminal buds of willow twigs and deposit an egg in 
each bud. The egg is very tiny, and it soon hatches 
into a larva almost equally minute, but in some way that 
we do not very well understand this larva is able to bend 
the energies of the twig to form a home for it. The bud 
starts to grows but unlike the other terminal buds beside 
it it cannot push ahead as a slender graceful branch ; 
instead it must stop and send its leaves out almost hori- 
zontally to form for this intruder a shelter and a food 
supply. So the leaves that else would take on so linear 
and delicate a grace, became the broad and clumsy scales 
of this monstrous cone. In the midst of all the larva 
Hves, absorbing the plant juices which serve for nourish- 
ment. 

The shelter which has done so much for it through 
the summer is obviously an excellent protection through 
the winter. So the larva remains in it unchanged 
until the approach of the following spring brings near 
the opportunity for the deposition of eggs for another 
brood. Then it changes to a pupa, soon to emerge as 
an adult fly. 

This fly belongs to the family Cecidomyiidae, which is 
composed of the gall-gnats. This species is called 
Cecidomyia strobiloides. 

If you press apart the scales of the pine-cone, you are 
likely to find other pinkish larvae snugly tucked away 
between the woolly surfaces of the scales. These are 
the larvae of another gall-fly which has wisely learned to 
take advantage of the unused chambers of the gall. Its 
eggs are probably deposited while the gall is developing. 
In a single gall there will be a great many more of these 
guest-fly larvae than of the original designer, for there is 
only one of the latter, while there are many of the former. 

149 



Nature Biographies. 



So it Is probable that if you keep the galls in glass jars, 
you will get both species of flies, the most of them being 
guest-flies. 

Of course the guest larvae have learned that they 
could have no safer place to pass the winter than that 
where they have developed. Consequently they follow 

the example of the host spe- 
cies in remaining in between 
the scales as larv^ until the 
approach of spring. Then 
they pupate and soon emerge 
as flies. 

This guest gall-fly belongs 
to the same family as the 
other. Entomologists call it 
Cecidomyia albovittata. 

If you examine carefully 

the flies you rear in the jars, 

you are likely to find some 

quite different from the 

others. Their bodies are 

smaller and more compact, 

and they have four wings 

instead of two. These are 

parasites, upon one or the 

other of the Cecidomyias, perhaps both. So you see 

that even this elaborate summer and winter shelter does 

not keep them safe from all enemies. 

The beetles form the great order Coleoptera, which 
includes many families and a vast number of species. 
The larv^ of many of these, especially such as burrow 
in the soil or in trees and logs, may readily be found 
during the winter months. Many of these require at 

150 




Fig. 135.— The Oak-plum Gall. 



Insects in Winter. 

least two years to complete their development so that 
they must pass at least one winter in the larval condi- 
tion. The beetle larvae are not silk spinners, so they 
cannot make hibernation cases like those of many of 
the Lepidoptera ; consequently they are seldom to be 
found save where they are protected by some other sort 
of shelter. 

The easiest place to find the larv^ of the Hymenop- 
tera in winter is in the numerous galls which they make 
upon various plants. The oak-plum gall ^ shown in Fig- 
ure 135 will serve as an example of these. This curious 
growth develops on the outside of the acorn cup. In 
autumn it is of a bright red colour. Inside, it is of a 
spongy texture, with the larva in a little cell of harder 
tissue in the centre. The outer portion becomes denser 
as the season advances, so that in winter the gall is 
often very hard. The little black fly into which the 
larva matures generally emerges in April. 

in. COCOONS AND CHRYSALIDS. 

When we think of insects in winter, the forms which 
are most likely to come to mind are the cocoons with 
their contained pupae. This seems at first glance the 
most natural way for an insect to pass the winter, yet 
were we to make a list of the winter stages of all the 
insects in a northern region, we probably should find 
that much less than half the species hibernate as 
pupae. 

This idea of the prevalence of the pupal stage of hiber- 
nation is probably due to the fact that several species of 
large and rather common moths pass the winter in con- 

^ Cynips querciis-prinms Riley. 



Nature Biographies. 



spicuous cocoons which are often found. Thus the 
Cecropia moth winters over in the large silken cocoon 
shown in Figure 1 14 (p. 1 19). This cocoon is about four 
inches in length by two inches in breadth. It may often 
be found attached to the twigs of a great variety of 
trees and shrubs. If you cut it open, you will find that 
the outer wall of silk is tough and impervious to 

water ; inside this you find a mass 
M of more loosely spun silk, and 

fft^ ^5^ lining the whole, another tough 

'"^'^^^^*^ wall. Inside the latter wall you 

will find the brown pupa, with 
the dried remains of the larval 
skin crowded into one end of 
the cavity. Notice how firmly 
the cocoon is attached to the 
twig by the silken threads of 
which it is made up. 

By keeping some of these co- 
coons in a large box, one is likely 
to oret the beautiful moths in 
May or June. As the season of 
emergence approaches it is worth 
while to keep the cocoons under 
daily observation so that per- 
chance you may see the moth as it first comes forth, 
when its body is distended and the wings mere shoulder 
tufts. A small stick or other support should be provided, 
so that the moth can crawl up and let its body hang 
vertically. Then you may be able to see the expansion 
of the wings as the blood is forced into the veins. 

One day last September a caterpillar of this Cecropia 
moth was brought to the studio. It was a 

152 




Flu. ijo. — ^cUjip.iLir uf Ce- 
cropia Moth. 



strange- 



Insects in Winter. 

looking creature with its immense bod}^ covered with 

many warty projections, some of which were bright coral 

red (Fig. 136). I placed it on a fresh apple tw^ig, of 

which it ate a fe\v of the leaves, but the next morning it 

had begun the construction of its cocoon by drawing 

some of the leaves in toward the twio^ and coverino^ them 

with silk. At first 

the caterpillar 

could be seen 

through the thin 

covering spinning 

its silken shroud, 

but soon the layers 

were so dense that 

it was hidden from 

view. 

Sometimes in- 
stead of a moth 
you may get from 
your cocoons four- 
winged ichneumon- 
flies. These are 
parasites w h i c h 
have destroyed the 
host and devel- 
oped at its expense, 
while on the trees 
the cocoons are 




Fig. 137. — Cocoon of Promethea Moth. 



often torn open by the hairy woodpecker which devours 
the pupae within. 

An entirely different cocoon, which is often found upon 
the twigs of barberry, black cherry, sassafras, and other 
shrubs and trees, is represented in Figures 137 and 138. 

153 



Nature Biographies. 



This is the cocoon of the Promethea moth, a large and 
handsome species common in our Northern states. 
The cocoon is of special interest because it shows a 
remarkable instinct on the part of the caterpillar that 
constructed it. If you examine the structure of the co- 
coon carefully, 
you see that a 
leaf forms the 
framework on 
w^ h i c h the 
silken web was 
spun. Some- 
times the leaf 
may have dis- 
appeared, but 
the impression 
of its midrib 
and principal 
veins is easily 
seen. Notice 
how cleverly 
it is attached 
to the twig by 
silken threads 
woven tightly 
around it. 

By keeping 
tj-ie promethea 
cocoons under observation late in spring or early in sum- 
mer, you may be able to see the moths develop. Some- 
times, however, you may get only a four-winged parasite 
for your pains. 

Our commonest species of the large swallow-tailed 

154 





Fig. 138. — Promethea Moth on Cocoon. 



Insects in W^iiiter. 



butterflies pass the winter in the chrysahs state. About 
gardens in which carrots, parsnips, or parsley have been 
growing one can frequently find during the autumn and 
winter months the chrysalis of the familiar black and yel- 
low Asterias butterfly (Fig. 139). The rather handsome 
caterpillars of this 
species (Fig. 140) 
are frequently 
common upon the 
plants named dur- 
ing the latter part 
of summer. When 
full grown, they 
wander about in 
search of shelter 
for the chrysalis 
period. When 
they find a fence 
or a board loosely 
resting on the 
ground, they spin 
a silken mesh in 
which to attach 
the hind end of 
the body, and a 
silken girdle to go 
over the thorax ; 
then they change 

to the chrysalis which hangs there naked and helpless 
during the long months of late autumn, winter, and early 
spring. It is not strange that during this period a large 
proportion of the chrysalids perish from the numerous 
enemies to whose attack they are exposed : birds, squir- 

155 




Fig. 139. — Asterias Butterfly on Goldenrod. 



Nature Biographies. 




Fig. 140. — Caterpillar of Asterias Butterfly. 

they have the power to conform theii 



rels, and mice 
are among 
these, not to 
mention the va- 
rious parasitic 
and predaceous 
insects. 

It is fortunate 
for these chrys- 
ahds that to a 
large extent 
colour to that of 
the surrounding surface. In the summer time the 
caterpillars frequently seek the shelter of herbaceous 
plants to spend the 
chrysalis period; 
they then soon take 
on the green colour 
of the plant. Last 
summer I found 
such a chrysalis 
attached to the stem 
of a pigweed [Che- 
iiop odium) ; it is 
represented in Fig- 
ure 141. The chrys- 
alis was of the same 
glaucous green col- 
our as the leaves 
and stems of the 
plant. The larva 
had spun its silken 

webs upon the stem Fig. 141, — Summer chrysalis of Asterias Butterfly. 

156 




Insects in Winter. 



and branches, a few threads going clear around to hold 
the rest in place. This was fortunate for the chrysalis, 
for much of the web had become loosened so that the 
support fell entirely upon the encircling threads ; the 
condition is shown in Figure 142. 

The winter chrysalids attached to dark, weather-beaten 
boards are generally of a dark grayish colour very similar 
to that of the sur- 
rounding surface. 

The beautiful 
Turnus swallowtail 
represented in Fig- 
ure 143 also passes 
the winter in the 
chrysalis state. But 
as its food consists 
of the leaves of vari- 
ous trees instead of 
garden vegetables, 
the chrysalis is not 
so often found by 
insect collectors. 

In the vicinity of a garden in which cabbages have 
been grown, a little search will nearly always bring to 
light the chrysalids of the common imported cabbage 
worm, the larva of the abundant white butterfly called 
Pieris rapce. These chrysalids vary much in colour, 
those against a dark background being in general darker 
than those against a light background. In England the 
observation of this fact led to some of the most interest- 
ing experiments on the relation of the colours of insects 
to their surroundings. These chrysalids appear to be 
much more exposed to the attack of enemies than are 

157 




Fig. 142. — A Nearer View of Same. 



Nature Biographies. 



those of the insects which pass the winter in tough 
cocoons ; and the mortahty from birds and other enemies 
is probably proportionately greater. Instead of a cocoon 
there is simply a loop of silk to hold the front end of the 
body in place, and a flat bunch of silk against the support 
to which the hind end is attached. These chrysalids may 
be found on fence boards, the sides of houses, barns or 

sheds, under sticks or 
stones, in almost any 
situation to which the 
worm may have wan- 
dered before taking on 
the chrysalis condition. 
Besides the variations 
in colour clue to the 
background there is 
often a colour variation 
due to parasitism. By 
putting some of the 
chrysalids in a glass jar 
you are likely to get 
w^hite butterflies from 
the healthy pupae, and 
tiny four-winged flies 
from those infested with 
parasites. 

The curious larvae of the sphinx moths go into the 
ground in autumn, soon changing to pup^ that remain 
in the soil through the winter. By so doing, they es- 
cape many enemies that would rejoice over such a supply 
of food as one of these pupae would furnish. This is true 
not only of the species that feed upon herbaceous plants, 
as in the case of the common tomato w^orm (Fig. 144), 

158 




Fig. 143. — The Turnus Butterfly. 



Insects in Winter. 

but also of those tliat feed upon the leax'es of trees. 
These pupa^ He in hollow cells in the earth without any 
sis^n of a cocoon or other coverinir. 




Fig. 144. — The Tomato Worm, 

There are various larvae of the great family Noctuidae 
— the night-flying moths — that have the same habit of 
going into the ground in autumn for the purpose of pu- 
pation. Perhaps 
the familiar 
zebra-caterpillar, 
which feeds 
upon cabbage, 
peas, and a con- 
siderable variety 
of other plants, 
is as good an ex- 
ample as any. 

The larvcc of 




Fig. 145. — Larva of Datana Moth. 



the hand-maid moths of the genus Datana, also hibernate 
as pupae in the ground. The ministra, or yellow-necked 
apple-tree caterpillar, is one of the most familiar species 

159 



Nature Biographies. 

of this genus. One of these larv^ is represented in. 
Figure 145 in the pecuhar attitude it assumes when dis- 
turbed. These insects feed in colonies, devouring the 
foHage as they go, so that their presence is generally 
shown by the denuded branches of their food-plants. 
When full grown they descend to the ground and pupate 
in cells in the soil, remaining unchanged until early the 



folio wins: summer. 



IV. THE ADULT. 



Very few Orthoptera pass the winter as adults. 
Among these are the grouse locusts, which late in 
autumn or early in spring, as well as in mild weather 
during winter when no snow is on the ground, may 
often be found under the edges of stones, logs, or 
boards, or among the fallen leaves along the borders of 
woods. These insects hibernate in this adult condition, 
relying upon the shelter they find and their dull incon- 
spicuous colours to enable them to escape from enemies. 

Comparatively few butterflies pass the winter in the 
adult condition. Those that do seek shelter, on the 
under sides of twigs, in hollow trees, in wood piles, and 
various similar situations, many of which are due to the 
presence of man. Under the original conditions in 
which the butterflies developed as species, probably a 
large proportion of them passed the winter on the bark 
of twigs, branches, or trunk. 

Most of these hibernatino^ butterflies belons: to one 
group; indeed in the Northern states a majority of 
them are to be found in two Q-enera, — Vanessa and 
Grapta. One peculiarity of the butterflies of these two 
genera is that the upper surface of the wings is much 
more brightly coloured than the under surface. When 

160 



mmmmmmmmmmmmmmtmmmmmmma^l^mmmt^mmmimmmKtMmM 



Insects in Winter. 

at rest, the wings are held vertically, the upper surfaces 
meeting and concealing each other, so that only the 
lower surfaces are exposed to sight. The general colour 
tone of the lower surface varies in different species, but 
in practically all of them it is grayish or brownish or 
blackish and has a curiously mottled appearance, sugges- 
tive of the effect of weathered bark or dead leaves seen 
at a little distance. There is, of course, an advantao^e to 
the butterflies in thus taking on the colour tones of their 
surroundings during the long period of exposure. 

We have not enough precise observations to indicate 
that these butterflies choose their winter position with 
reference to the tint of the exposed surface of the wings. 
Such observations would be of o-reat interest. That 
they may do so, seems probable. In Europe, as stated 
by Mr. S. H. Scudder, " Landois saw the butterfly, lua- 
chis to, take up its winter quarters in an ivy, hanging 
from a branch by its hind legs, folding all its other legs 
on its breast and closing its wings. During a warm 
spell in the early spring it disappeared only, when the 
w^eather again changed, to return to the same spot and 
reassume its former position." 

A good many species of the true bugs — Hemiptera 

— hibernate as adults. They may be found under loose 
bark and in the rubbish in fence corners and about stone 
piles. Many species of the two-winged flies — Diptera 

— also hibernate in this stage. Every one is familiar 
with the wav in which house-flies and related forms con- 
gregate in attics through the autumn months. A little 
search in cellars and basements will also generally bring- 
to light various mosquitoes that have sought out these 
places for their wdnter quarters. 

Among the ants, bees, w^asps, and their allies, hiberna- 

i6i 



Nature Biographies. 

tion as adults is a common experience. The wasps, 
hornets, yellow-jackets, and bumblebees are all good ex- 
amples of this, while many of the ichneumon-flies and 
gall-flies also hibernate in the adult condition. 

It is among the beetles, however, that the entomolo- 
gist expects to find the largest number of species and 
specimens in his collecting from late fall to early spring. 
He finds the adults of this order in all sorts of situations. 
Beneath the soil, the click-beetles and May-beetles are 
resting in their pupal cavities, their outer tissues harden- 
ing preparatory to coming forth in spring. At the sur- 
face of the soil under shelter of many sorts are ladybird 
beetles and ground beetles, often collected together in 
great numbers, as well as a host of other sorts, scattered 
singly here and there. Under the bark of trees and 
logs are beetles of many kinds, while in rotten wood and 
among the fallen leaves in the forest there are many 
others. 



162 



■MHHIHMiHHHHIH^HBHIHHHHHHHHHi 



INDEX. 



American tent caterpillar, 
An insect potter, 102. 
Antiopa butterfly, 71. 
Ants and aphides, 140. 
Aplodes riibifrontalia. 39. 
Apple aphis, 139. 
Argynnis butterflies, 143. 
Asterias butterfly, 155. 
Atalanta butterfly, ri2. 



B. 



12. 



Bud worm, 145. 

Butterflies, catching, with a camera, 96. 

Butterfly, the making of a, i . 



Cabbage butterfly, 157. 

Caccecia cerasivorana, 64. 

Calosoma scrutator. 86. 

Camera and the entomologist, the, 107. 

Carolina locust, 89. 

Catching butterflies with a camera, 96 

Caterpillar hunter, 86. 

Cecidoi7iyia albovittata^ 150. 

Cecidoinyia salicis, 146. 

Cecidomyia strobiloides, 149. 

Cecropia emperor moth, 117, 152. 

Clisiocajttpa americana, 12. 

Clisiocainpa dis stria, 40. 

Cutworms, 144. 

Cynips qiierais-prunns, 151. 



D. 

Danais arc/uppus, 3. 
Daiiais plexappus, 3. 
Datana moths, 159. 
Diapheromera femorata, 58. 
Dissosteira Carolina, 89. 



Einpusa aphidis, 93. 
Eumenes fraterna, 102. 

F. 

Fall web-worm, 114. 
Forest tent caterpillar, 40. 



Goldenrod gall, 114. 
Grapto, 160. 

H. 

• Hand-maid moths. 159. 
Hunter's butterfly, 98. 

I. 

Inachis 20, 161. 
Insect parasites, 122. 
Insect potter, an, 102. 
Insects in winter, 132. 
lo moth. III, 125. 

163 



Index. 



Katydid, angular- winged, 136. 

L. 

Leaf miners, 145. 

Limeiiitis disippus, 1 1 . 
Linineria fitgitiva, 1 24. 
Locust mummies, 89. 

M. 

Making of a butterfly, the, i. 
Melaiwpliis punctiilatiis, 135. 
Melanoxanthus, 139. 
Microgaster parasites, 128. 
Moth that failed, a, 128. 
Mourning-cloak butterfly, 71. 

N. 
Nectarophora pi si, 93. 



O. 



Oak-plum gall, 150. 
Orgyia ajitiqna, 142. 
Orgyia leucostigjna, 142. 
Oyster-shell bark-louse, 141, 



Painted beauty butterfly. 98. 
Parasite of butterfly eggs, a, 126. 



Pier is rapcp, 157, 
Pine-cone vvil low-gall, 138. 
Pine locust, 134. 
Polyphemus moth, iir. 
Promethea moth, 117, 154. 

R. 

Red-humped apple caterpillar, 122. 
Rural impostor, a, 35. 



Sphinx moths, 158. 

Studies of walking-sticks, 58. 

Sweet fern caterpillar, 36. 



Teleiiomus graptcu, 128. 
Tomato worm, 159. 
Troilus butterfly, 1 1 1 . 
Turnus butterfly, 157. 

V. 

Vanessa, 160. 

Vanessa antiopa. 71. 
Viceroy butterfly, the, 11. 

W. 

Walking-sticks, studies of, 58. 
Willow-gall, oval, 146. 
Willow-gall, pine-cone, 148. 



164 



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No 3 7 j!jN 20 im 



LIBRARY OF CONGRESS 




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